diff --git a/.gitignore b/.gitignore
index 6bfe34914..cb42ae62f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,3 +37,4 @@ modoboa.kdev4
 .kateproject
 test_project/cert.crt
 test_project/cert.key
+test_project/envfile
diff --git a/frontend/package.json b/frontend/package.json
index 68347ab85..ca4a9b004 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -26,6 +26,7 @@
     "axios": "^1.8.2",
     "core-js": "^3.37.1",
     "debounce": "^2.1.0",
+    "filesize": "^10.1.6",
     "js-cookie": "^3.0.5",
     "luxon": "^3.4.4",
     "oidc-client-ts": "^3.0.1",
diff --git a/frontend/src/api/webmail.js b/frontend/src/api/webmail.js
new file mode 100644
index 000000000..5edbbe293
--- /dev/null
+++ b/frontend/src/api/webmail.js
@@ -0,0 +1,25 @@
+import repository from './repository'
+
+export default {
+  getUserMailboxes(mailbox) {
+    const params = {}
+    if (mailbox) {
+      params.mailbox = mailbox
+    }
+    return repository.get('/webmail/mailboxes/', { params })
+  },
+  getMailboxEmails(mailbox, options) {
+    const params = {
+      mailbox,
+      ...options,
+    }
+    return repository.get(`/webmail/emails/`, { params })
+  },
+  getEmailContent(mailbox, mailid) {
+    const params = {
+      mailbox,
+      mailid,
+    }
+    return repository.get(`/webmail/emails/content/`, { params })
+  },
+}
diff --git a/frontend/src/components/shared/NavBar.vue b/frontend/src/components/shared/NavBar.vue
index 7628d8d0c..6cc5c4a59 100644
--- a/frontend/src/components/shared/NavBar.vue
+++ b/frontend/src/components/shared/NavBar.vue
@@ -21,7 +21,11 @@
       </v-btn>
     </div>
 
-    <v-list nav>
+    <v-list
+      :density="layoutStore.compactLeftMenu ? 'compact' : 'default'"
+      :lines="layoutStore.compactLeftMenu ? false : true"
+      nav
+    >
       <template v-for="item in menuItems" :key="item.text">
         <template v-if="displayMenuItem(item)">
           <v-list-subheader v-if="item.subheader" class="text-white">
@@ -89,7 +93,7 @@
 <script setup>
 import { useRouter } from 'vue-router'
 import { ref, computed, onMounted } from 'vue'
-import { useGlobalStore, useAuthStore } from '@/stores'
+import { useGlobalStore, useAuthStore, useLayoutStore } from '@/stores'
 
 const props = defineProps({
   color: {
@@ -109,6 +113,7 @@ const props = defineProps({
 
 const globalStore = useGlobalStore()
 const authStore = useAuthStore()
+const layoutStore = useLayoutStore()
 const router = useRouter()
 
 const rail = ref(false)
diff --git a/frontend/src/components/webmail/EmailList.vue b/frontend/src/components/webmail/EmailList.vue
new file mode 100644
index 000000000..5f5af08eb
--- /dev/null
+++ b/frontend/src/components/webmail/EmailList.vue
@@ -0,0 +1,113 @@
+<template>
+  <v-card class="mt-6 mb-2">
+    <v-toolbar color="white" flat>
+      <v-checkbox class="mr-4" hide-details />
+
+      <v-text-field
+        v-model="search"
+        prepend-inner-icon="mdi-magnify"
+        :placeholder="$gettext('Search')"
+        variant="outlined"
+        single-line
+        flat
+        hide-details
+        density="compact"
+        class="flex-grow-0 w-33 mr-4"
+      ></v-text-field>
+    </v-toolbar>
+  </v-card>
+  <v-skeleton-loader v-if="loading" type="card@2"></v-skeleton-loader>
+  <template v-else>
+    <v-card
+      v-for="email in emails"
+      :key="email.imapid"
+      density="compact"
+      class="mb-2"
+    >
+      <v-card-text
+        class="d-flex align-center"
+        :class="{ 'font-weight-bold': email.style === 'unseen' }"
+      >
+        <v-checkbox :value="email.imapid" hide-details />
+        <v-btn
+          :icon="email.flagged ? 'mdiu-star' : 'mdi-star-outline'"
+          variant="flat"
+        />
+        <div class="ml-4 clickable" @click="openEmail(email.imapid)">
+          <div>{{ email.subject }}</div>
+          <div class="mt-1 text-grey">
+            <span
+              v-if="email.from_address.name"
+              :title="email.from_address.address"
+              >{{ email.from_address.name }}</span
+            >
+            <span v-else>{{ email.from_address.address }}</span>
+          </div>
+        </div>
+        <v-spacer />
+        <div class="text-right">
+          <div>{{ email.date }}</div>
+          <div class="mt-1">
+            <v-icon v-if="email.answered" icon="mdi-reply-outline" />
+            <v-icon v-if="email.forwarded" icon="mdi-share-outline" />
+            <v-icon v-if="email.attachments" icon="mdi-paperclip" />
+            <span class="text-grey">{{ $filesize(email.size) }}</span>
+          </div>
+        </div>
+      </v-card-text>
+    </v-card>
+  </template>
+</template>
+
+<script setup>
+import { ref, watch } from 'vue'
+import { useRouter } from 'vue-router'
+import api from '@/api/webmail'
+
+const props = defineProps({
+  mailbox: {
+    type: String,
+    default: 'INBOX',
+  },
+})
+
+const router = useRouter()
+
+const loading = ref(false)
+const emails = ref([])
+const search = ref('')
+
+const openEmail = (emailid) => {
+  router.push({
+    name: 'EmailView',
+    query: { mailbox: props.mailbox, mailid: emailid },
+  })
+}
+
+watch(
+  () => props.mailbox,
+  (value) => {
+    emails.value = []
+    loading.value = true
+    api
+      .getMailboxEmails(value, {})
+      .then((resp) => {
+        emails.value = resp.data
+        loading.value = false
+      })
+      .catch(() => {
+        loading.value = false
+      })
+  },
+  { immediate: true }
+)
+</script>
+
+<style lang="scss" scoped>
+.v-card-text {
+  padding: 0;
+}
+.clickable {
+  cursor: pointer;
+}
+</style>
diff --git a/frontend/src/components/webmail/MailboxList.vue b/frontend/src/components/webmail/MailboxList.vue
new file mode 100644
index 000000000..5588d374c
--- /dev/null
+++ b/frontend/src/components/webmail/MailboxList.vue
@@ -0,0 +1,103 @@
+<template>
+  <div>
+    <div
+      v-for="mailbox in props.mailboxes"
+      :key="mailbox.name"
+      class="py-1 pl-3 text-body-2"
+    >
+      <div
+        :class="getBackgroundColorClass(mailbox)"
+        class="d-flex mailbox pa-1 align-center"
+        @click="$emit('mailboxSelected', mailbox)"
+        @mouseover="setHover(mailbox, true)"
+        @mouseleave="setHover(mailbox, false)"
+      >
+        <v-icon :icon="iconByMailboxType[mailbox.type]" class="mr-4" />
+        {{ getMailboxLabel(mailbox) }}
+        <v-spacer />
+        <v-btn
+          v-if="mailbox.sub"
+          :icon="getMailboxState(mailbox) ? 'mdi-minus' : 'mdi-plus'"
+          size="xsmall"
+          variant="flat"
+          color="transparent"
+          @click.stop="toggleMailbox(mailbox)"
+        />
+      </div>
+      <MailboxList
+        v-if="getMailboxState(mailbox) && mailbox.sub && mailbox.sub.length"
+        :mailboxes="mailbox.sub"
+        class="mt-1"
+        @mailbox-selected="(mailbox) => $emit('mailboxSelected', mailbox)"
+      />
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import { useRoute } from 'vue-router'
+import api from '@/api/webmail'
+
+const route = useRoute()
+
+const props = defineProps({
+  mailboxes: {
+    type: Array,
+    default: null,
+  },
+})
+const emit = defineEmits(['mailboxSelected'])
+
+const iconByMailboxType = {
+  inbox: 'mdi-inbox',
+  draft: 'mdi-file',
+  junk: 'mdi-fire',
+  sent: 'mdi-email-fast-outline',
+  trash: 'mdi-trash-can-outline',
+  normal: 'mdi-folder-outline',
+}
+
+const hoverStates = ref({})
+const mailboxStates = ref({})
+
+function getMailboxLabel(mailbox) {
+  return mailbox.label.split('/').pop()
+}
+
+function setHover(mailbox, value) {
+  hoverStates.value[mailbox.name] = value
+}
+
+function getBackgroundColorClass(mailbox) {
+  if (route.query.mailbox === mailbox.name) {
+    return 'bg-primary-lighten-1'
+  }
+  return hoverStates.value[mailbox.name] ? 'bg-primary-lighten-1' : 'bg-primary'
+}
+
+function getMailboxState(mailbox) {
+  return mailboxStates.value[mailbox.name]
+}
+
+function toggleMailbox(mailbox) {
+  if (!mailboxStates.value[mailbox.name]) {
+    mailboxStates.value[mailbox.name] = false
+  }
+  mailboxStates.value[mailbox.name] = !mailboxStates.value[mailbox.name]
+  if (mailboxStates.value[mailbox.name] && !mailbox.sub.length) {
+    api.getUserMailboxes(mailbox.name).then((resp) => {
+      mailbox.sub = resp.data
+    })
+  }
+}
+</script>
+
+<style scoped lang="scss">
+.mailbox {
+  cursor: pointer;
+  &:hover {
+    border-radius: 5px;
+  }
+}
+</style>
diff --git a/frontend/src/layouts/connected/ConnectedLayout.vue b/frontend/src/layouts/connected/ConnectedLayout.vue
index 26e059418..2f9a0b60c 100644
--- a/frontend/src/layouts/connected/ConnectedLayout.vue
+++ b/frontend/src/layouts/connected/ConnectedLayout.vue
@@ -1,6 +1,8 @@
 <template>
   <v-app>
-    <NavBar :color="color" :menu-items="menuItems" />
+    <slot name="navbar">
+      <NavBar :color="color" :menu-items="menuItems" />
+    </slot>
     <TopMenu :user="authUser" />
     <ConnectedView />
     <v-snackbar
diff --git a/frontend/src/layouts/webmail/WebmailLayout.vue b/frontend/src/layouts/webmail/WebmailLayout.vue
new file mode 100644
index 000000000..ef0322b32
--- /dev/null
+++ b/frontend/src/layouts/webmail/WebmailLayout.vue
@@ -0,0 +1,59 @@
+<template>
+  <ConnectedLayout>
+    <template #navbar>
+      <v-navigation-drawer
+        v-model="drawer"
+        :rail="rail"
+        permanent
+        color="primary"
+        app
+      >
+        <div class="d-flex align-center">
+          <v-img
+            src="@/assets/Modoboa_RVB-BLANC-SANS.png"
+            max-width="190"
+            class="logo"
+          />
+          <v-btn
+            :icon="rail ? 'mdi-chevron-right' : 'mdi-chevron-left'"
+            variant="text"
+            @click.stop="rail = !rail"
+          >
+          </v-btn>
+        </div>
+
+        <MailboxList
+          :mailboxes="userMailboxes"
+          class="mr-2"
+          @mailbox-selected="openMailbox"
+        />
+      </v-navigation-drawer>
+    </template>
+  </ConnectedLayout>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import { useRouter } from 'vue-router'
+import ConnectedLayout from '@/layouts/connected/ConnectedLayout.vue'
+import MailboxList from '@/components/webmail/MailboxList.vue'
+import api from '@/api/webmail'
+
+const router = useRouter()
+
+const drawer = ref(true)
+const rail = ref(false)
+const userMailboxes = ref([])
+
+function openMailbox(mailbox) {
+  console.log(mailbox)
+  router.push({
+    name: 'MailboxView',
+    query: { mailbox: mailbox.name },
+  })
+}
+
+api.getUserMailboxes().then((resp) => {
+  userMailboxes.value = resp.data
+})
+</script>
diff --git a/frontend/src/plugins/filters.js b/frontend/src/plugins/filters.js
index e82fc5a30..345cab679 100644
--- a/frontend/src/plugins/filters.js
+++ b/frontend/src/plugins/filters.js
@@ -1,5 +1,6 @@
 import gettext from './gettext'
 import { DateTime } from 'luxon'
+import { filesize } from 'filesize'
 
 const { $gettext } = gettext
 
@@ -17,5 +18,8 @@ export default {
       clamp = clamp || '...'
       return value.length > length ? value.slice(0, length) + clamp : value
     }
+    app.config.globalProperties.$filesize = (value) => {
+      return filesize(value, { locale: gettext.current })
+    }
   },
 }
diff --git a/frontend/src/router/index.js b/frontend/src/router/index.js
index e9fce25ce..dc1ba3761 100644
--- a/frontend/src/router/index.js
+++ b/frontend/src/router/index.js
@@ -270,7 +270,6 @@ const routes = [
   },
   {
     path: '/user',
-    component: () => import('@/layouts/user/UserLayout.vue'),
     meta: {
       requiresAuth: true,
     },
@@ -285,6 +284,7 @@ const routes = [
       },
       {
         path: 'contacts',
+        component: () => import('@/layouts/user/UserLayout.vue'),
         meta: {
           requiresAuth: true,
         },
@@ -301,6 +301,7 @@ const routes = [
       },
       {
         path: 'calendars',
+        component: () => import('@/layouts/user/UserLayout.vue'),
         meta: {
           requiresAuth: true,
         },
@@ -315,6 +316,31 @@ const routes = [
           },
         ],
       },
+      {
+        path: 'webmail',
+        component: () => import('@/layouts/webmail/WebmailLayout.vue'),
+        meta: {
+          requiresAuth: true,
+        },
+        children: [
+          {
+            path: '',
+            name: 'MailboxView',
+            component: () => import('@/views/webmail/MailboxView.vue'),
+            meta: {
+              requiresAuth: true,
+            },
+          },
+          {
+            path: 'view',
+            name: 'EmailView',
+            component: () => import('@/views/webmail/EmailView.vue'),
+            meta: {
+              requiresAuth: true,
+            },
+          },
+        ],
+      },
     ],
   },
   {
diff --git a/frontend/src/stores/layout.store.js b/frontend/src/stores/layout.store.js
index 7767d2dd7..919ab4d5c 100644
--- a/frontend/src/stores/layout.store.js
+++ b/frontend/src/stores/layout.store.js
@@ -3,6 +3,7 @@ import { defineStore } from 'pinia'
 
 export const useLayoutStore = defineStore('layout', () => {
   const leftMenuItems = ref([])
+  const compactLeftMenu = ref(false)
 
   function setLeftMenuItems(items) {
     leftMenuItems.value = items
@@ -10,10 +11,12 @@ export const useLayoutStore = defineStore('layout', () => {
 
   async function $reset() {
     leftMenuItems.value = []
+    compactLeftMenu.value = false
   }
 
   return {
     leftMenuItems,
+    compactLeftMenu,
     setLeftMenuItems,
     $reset,
   }
diff --git a/frontend/src/views/webmail/EmailView.vue b/frontend/src/views/webmail/EmailView.vue
new file mode 100644
index 000000000..bdbae8a1b
--- /dev/null
+++ b/frontend/src/views/webmail/EmailView.vue
@@ -0,0 +1,50 @@
+<template>
+  <v-toolbar color="white" class="mt-12">
+    <v-btn variant="tonal" @click="close">
+      <v-icon icon="mdi-arrow-left" />
+      {{ $gettext('Back') }}
+    </v-btn>
+    <v-btn color="primary">
+      {{ $gettext('Reply') }}
+    </v-btn>
+  </v-toolbar>
+
+  <div v-if="email" class="mt-4">
+    <h3>{{ email.subject }}</h3>
+    <div>{{ email.from_address.name }}</div>
+    <iframe class="email-frame" />
+  </div>
+</template>
+
+<script setup>
+import { nextTick, onMounted, ref } from 'vue'
+import { useRoute } from 'vue-router'
+import api from '@/api/webmail'
+
+const route = useRoute()
+
+const email = ref(null)
+
+onMounted(() => {
+  api.getEmailContent(route.query.mailbox, route.query.mailid).then((resp) => {
+    email.value = resp.data
+    nextTick(() => {
+      const iframe = document.createElement('iframe')
+      iframe.classList.add('email-frame')
+      document.querySelector('iframe').replaceWith(iframe)
+      const iframeDoc = iframe.contentDocument
+      iframeDoc.write(email.value.body)
+      iframeDoc.close()
+    })
+  })
+})
+</script>
+
+<style>
+.email-frame {
+  width: 100%;
+  min-height: 1000px;
+  border: none;
+  margin-top: 10px;
+}
+</style>
diff --git a/frontend/src/views/webmail/MailboxView.vue b/frontend/src/views/webmail/MailboxView.vue
new file mode 100644
index 000000000..48b6136d3
--- /dev/null
+++ b/frontend/src/views/webmail/MailboxView.vue
@@ -0,0 +1,10 @@
+<template>
+  <div class="text-h5 ml-4">
+    {{ $gettext('Webmail') }}
+  </div>
+  <EmailList :mailbox="$route.query.mailbox || 'INBOX'" />
+</template>
+
+<script setup>
+import EmailList from '@/components/webmail/EmailList.vue'
+</script>
diff --git a/frontend/yarn.lock b/frontend/yarn.lock
index 4822245f3..d179e98b4 100644
--- a/frontend/yarn.lock
+++ b/frontend/yarn.lock
@@ -1044,6 +1044,11 @@ file-entry-cache@^8.0.0:
   dependencies:
     flat-cache "^4.0.0"
 
+filesize@^10.1.6:
+  version "10.1.6"
+  resolved "https://registry.yarnpkg.com/filesize/-/filesize-10.1.6.tgz#31194da825ac58689c0bce3948f33ce83aabd361"
+  integrity sha512-sJslQKU2uM33qH5nqewAwVB2QgR6w1aMNsYUp3aN5rMRyXEwJGmZvaWzeJFNTOXWlHQyBFCWrdj3fV/fsTOX8w==
+
 fill-range@^7.1.1:
   version "7.1.1"
   resolved "https://registry.yarnpkg.com/fill-range/-/fill-range-7.1.1.tgz#44265d3cac07e3ea7dc247516380643754a05292"
diff --git a/modoboa/calendars/apps.py b/modoboa/calendars/apps.py
index ffbace58f..cec54431e 100644
--- a/modoboa/calendars/apps.py
+++ b/modoboa/calendars/apps.py
@@ -1,4 +1,4 @@
-"""AppConfig for radicale."""
+"""AppConfig for calendars."""
 
 from django.apps import AppConfig
 
diff --git a/modoboa/core/api/v2/viewsets.py b/modoboa/core/api/v2/viewsets.py
index dc4e150f3..83abf419a 100644
--- a/modoboa/core/api/v2/viewsets.py
+++ b/modoboa/core/api/v2/viewsets.py
@@ -166,13 +166,13 @@ class AccountViewSet(core_v1_viewsets.AccountViewSet):
                 "description": _("Address book"),
                 "url": "/user/contacts",
             },
-            # {
-            #     "name": "webmail",
-            #     "label": _("Webmail"),
-            #     "icon": "mdi-at",
-            #     "description": _("Webmail"),
-            #     "url": "/user/webmail",
-            # }
+            {
+                "name": "webmail",
+                "label": _("Webmail"),
+                "icon": "mdi-at",
+                "description": _("Webmail"),
+                "url": "/user/webmail",
+            },
         ]
         apps += exts_pool.get_available_apps()
         serializer = serializers.ModoboaApplicationSerializer(apps, many=True)
diff --git a/modoboa/lib/email_utils.py b/modoboa/lib/email_utils.py
index 6c2501dfb..a7d56f2cf 100644
--- a/modoboa/lib/email_utils.py
+++ b/modoboa/lib/email_utils.py
@@ -35,7 +35,7 @@ class EmailAddress:
         else:
             self.fulladdress = self.address
 
-    def __str__(self):
+    def __str__(self) -> str:
         return self.fulladdress
 
 
@@ -117,7 +117,7 @@ class Email:
 
         return self._body
 
-    def get_header(self, msg, header):
+    def get_header(self, msg, header: str) -> str:
         # msg parameter to maintain compatibility with
         # modoboa_webmail.lib.imapemail.ImapEmail
         if header in msg:
diff --git a/modoboa/urls_api_v2.py b/modoboa/urls_api_v2.py
index ad8671dc7..7432a38bd 100644
--- a/modoboa/urls_api_v2.py
+++ b/modoboa/urls_api_v2.py
@@ -22,6 +22,7 @@ urlpatterns = [
     path("", include("modoboa.sievefilters.api.v2.urls")),
     path("", include("modoboa.contacts.urls")),
     path("", include("modoboa.calendars.urls")),
+    path("webmail/", include("modoboa.webmail.urls")),
 ]
 
 urlpatterns += exts_pool.get_urls(category="api")
diff --git a/modoboa/webmail/__init__.py b/modoboa/webmail/__init__.py
new file mode 100644
index 000000000..2ab867c5e
--- /dev/null
+++ b/modoboa/webmail/__init__.py
@@ -0,0 +1 @@
+default_app_config = "modoboa.webmail.apps.WebmailConfig"
diff --git a/modoboa/webmail/app_settings.py b/modoboa/webmail/app_settings.py
new file mode 100644
index 000000000..0f77cbd0d
--- /dev/null
+++ b/modoboa/webmail/app_settings.py
@@ -0,0 +1,268 @@
+import collections
+
+from django.utils.translation import gettext_lazy
+
+
+GLOBAL_PARAMETERS_STRUCT = collections.OrderedDict(
+    [
+        (
+            "general",
+            {
+                "label": gettext_lazy("General"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "max_attachment_size",
+                            {
+                                "label": gettext_lazy("Maximum attachment size"),
+                                "help_text": gettext_lazy(
+                                    "Maximum attachment size in bytes (or KB, MB, GB if specified)"
+                                ),
+                            },
+                        )
+                    ]
+                ),
+            },
+        ),
+        (
+            "imap",
+            {
+                "label": gettext_lazy("IMAP settings"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "imap_server",
+                            {
+                                "label": gettext_lazy("Server address"),
+                                "help_text": gettext_lazy(
+                                    "Address of your IMAP server"
+                                ),
+                            },
+                        ),
+                        (
+                            "imap_secured",
+                            {
+                                "label": gettext_lazy("Use a secured connection"),
+                                "help_text": gettext_lazy(
+                                    "Use a secured connection to access IMAP server"
+                                ),
+                            },
+                        ),
+                        (
+                            "imap_port",
+                            {
+                                "label": gettext_lazy("Server port"),
+                                "help_text": gettext_lazy(
+                                    "Listening port of your IMAP server"
+                                ),
+                            },
+                        ),
+                    ]
+                ),
+            },
+        ),
+        (
+            "smtp",
+            {
+                "label": gettext_lazy("SMTP settings"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "smtp_server",
+                            {
+                                "label": gettext_lazy("Server address"),
+                                "help_text": gettext_lazy(
+                                    "Address of your SMTP server"
+                                ),
+                            },
+                        ),
+                        (
+                            "smtp_secured_mode",
+                            {
+                                "label": gettext_lazy("Secured connection mode"),
+                                "help_text": gettext_lazy(
+                                    "Use a secured connection to access SMTP server"
+                                ),
+                            },
+                        ),
+                        (
+                            "smtp_port",
+                            {
+                                "label": gettext_lazy("Server port"),
+                                "help_text": gettext_lazy(
+                                    "Listening port of your SMTP server"
+                                ),
+                            },
+                        ),
+                        (
+                            "smtp_authentication",
+                            {
+                                "label": gettext_lazy("Authentication required"),
+                                "help_text": gettext_lazy(
+                                    "Server needs authentication"
+                                ),
+                            },
+                        ),
+                    ]
+                ),
+            },
+        ),
+    ]
+)
+
+USER_PREFERENCES_STRUCT = collections.OrderedDict(
+    [
+        (
+            "display",
+            {
+                "label": gettext_lazy("Display"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "displaymode",
+                            {
+                                "label": gettext_lazy("Default message display mode"),
+                                "help_text": gettext_lazy(
+                                    "The default mode used when displaying a message"
+                                ),
+                            },
+                        ),
+                        (
+                            "enable_links",
+                            {
+                                "label": gettext_lazy("Enable HTML links display"),
+                                "help_text": gettext_lazy(
+                                    "Enable/Disable HTML links display"
+                                ),
+                            },
+                        ),
+                        (
+                            "messages_per_page",
+                            {
+                                "label": gettext_lazy(
+                                    "Number of displayed emails per page"
+                                ),
+                                "help_text": gettext_lazy(
+                                    "Sets the maximum number of messages displayed in a page"
+                                ),
+                            },
+                        ),
+                        (
+                            "refresh_interval",
+                            {
+                                "label": gettext_lazy(
+                                    "Number of displayed emails per page"
+                                ),
+                                "help_text": gettext_lazy(
+                                    "Sets the maximum number of messages displayed in a page"
+                                ),
+                            },
+                        ),
+                        (
+                            "mboxes_col_width",
+                            {
+                                "label": gettext_lazy("Folder container's width"),
+                                "help_text": gettext_lazy(
+                                    "The width of the folder list container"
+                                ),
+                            },
+                        ),
+                    ]
+                ),
+            },
+        ),
+        (
+            "folders",
+            {
+                "label": gettext_lazy("Folders"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "trash_folder",
+                            {
+                                "label": gettext_lazy("Trash folder"),
+                                "help_text": gettext_lazy(
+                                    "Folder where deleted messages go"
+                                ),
+                            },
+                        ),
+                        (
+                            "sent_folder",
+                            {
+                                "label": gettext_lazy("Sent folder"),
+                                "help_text": gettext_lazy(
+                                    "Folder where copies of sent messages go"
+                                ),
+                            },
+                        ),
+                        (
+                            "drafts_folder",
+                            {
+                                "label": gettext_lazy("Drafts folder"),
+                                "help_text": gettext_lazy("Folder where drafts go"),
+                            },
+                        ),
+                        (
+                            "junk_folder",
+                            {
+                                "label": gettext_lazy("Junk folder"),
+                                "help_text": gettext_lazy(
+                                    "Folder where junk messages should go"
+                                ),
+                            },
+                        ),
+                    ]
+                ),
+            },
+        ),
+        (
+            "composing",
+            {
+                "label": gettext_lazy("Composing messages"),
+                "params": collections.OrderedDict(
+                    [
+                        (
+                            "editor",
+                            {
+                                "label": gettext_lazy("Default editor"),
+                                "help_text": gettext_lazy(
+                                    "The default editor to use when composing a message"
+                                ),
+                            },
+                        ),
+                        (
+                            "signature",
+                            {
+                                "label": gettext_lazy("Signature text"),
+                                "help_text": gettext_lazy(
+                                    "User defined email signature"
+                                ),
+                            },
+                        ),
+                    ]
+                ),
+            },
+        ),
+    ]
+)
+
+
+def load_settings():
+    """Load webmail settings."""
+    from modoboa.parameters import tools as param_tools
+    from modoboa.webmail import serializers
+
+    param_tools.registry.add2(
+        "global",
+        "webmail",
+        gettext_lazy("Webmail"),
+        GLOBAL_PARAMETERS_STRUCT,
+        serializers.GlobalParametersSerializer,
+    )
+    param_tools.registry.add2(
+        "user",
+        "webmail",
+        gettext_lazy("Webmail"),
+        USER_PREFERENCES_STRUCT,
+        serializers.UserPreferencesSerializer,
+    )
diff --git a/modoboa/webmail/apps.py b/modoboa/webmail/apps.py
new file mode 100644
index 000000000..37cdd330c
--- /dev/null
+++ b/modoboa/webmail/apps.py
@@ -0,0 +1,15 @@
+"""AppConfig for webmail."""
+
+from django.apps import AppConfig
+
+
+class WebmailConfig(AppConfig):
+    """App configuration."""
+
+    name = "modoboa.webmail"
+    verbose_name = "Modoboa webmail"
+
+    def ready(self):
+        from modoboa.webmail.app_settings import load_settings
+
+        load_settings()
diff --git a/modoboa/webmail/constants.py b/modoboa/webmail/constants.py
new file mode 100644
index 000000000..31e5ffbf2
--- /dev/null
+++ b/modoboa/webmail/constants.py
@@ -0,0 +1,32 @@
+"""Webmail constants."""
+
+from enum import Enum
+
+from django.utils.translation import gettext_lazy as _
+
+
+MAILBOX_TYPES = ["inbox", "draft", "sent", "junk", "trash", "normal"]
+
+
+class SmtpConnectionMode(Enum):
+    NONE = "none"
+    STARTTLS = "starttls"
+    TLS = "ssl"
+
+
+SMTP_CONNECTION_MODES = [
+    (SmtpConnectionMode.NONE.value, _("None")),
+    (SmtpConnectionMode.STARTTLS.value, "STARTTLS"),
+    (SmtpConnectionMode.TLS.value, "SSL/TLS"),
+]
+
+
+class DisplayMode(Enum):
+    PLAIN = "plain"
+    HTML = "html"
+
+
+DISPLAY_MODES = [
+    (DisplayMode.PLAIN.value, "text"),
+    (DisplayMode.HTML.value, "html"),
+]
diff --git a/modoboa/webmail/exceptions.py b/modoboa/webmail/exceptions.py
new file mode 100644
index 000000000..1d188dd43
--- /dev/null
+++ b/modoboa/webmail/exceptions.py
@@ -0,0 +1,33 @@
+"""Webmail custom exceptions."""
+
+import re
+
+from django.utils.translation import gettext as _
+
+from modoboa.lib.exceptions import ModoboaException, InternalError
+
+
+class WebmailInternalError(InternalError):
+    errorexpr = re.compile(r"\[([^\]]+)\]\s*([^\.]+)")
+
+    def __init__(self, reason, ajax=False):
+        match = WebmailInternalError.errorexpr.match(reason)
+        if not match:
+            self.reason = reason
+        else:
+            self.reason = f"{_('Server response')}: {match.group(2)}"
+        self.ajax = ajax
+
+    def __str__(self):
+        return self.reason
+
+
+class ImapError(ModoboaException):
+
+    http_code = 500
+
+    def __init__(self, reason):
+        self.reason = reason
+
+    def __str__(self):
+        return str(self.reason)
diff --git a/modoboa/webmail/lib/__init__.py b/modoboa/webmail/lib/__init__.py
new file mode 100644
index 000000000..f5204776f
--- /dev/null
+++ b/modoboa/webmail/lib/__init__.py
@@ -0,0 +1,32 @@
+from .attachments import (
+    create_mail_attachment,
+    save_attachment,
+    clean_attachments,
+    set_compose_session,
+    AttachmentUploadHandler,
+)
+from .imapemail import ImapEmail, ReplyModifier, ForwardModifier
+from .imaputils import BodyStructure, IMAPconnector, get_imapconnector, separate_mailbox
+from .signature import EmailSignature
+from .utils import decode_payload, WebmailNavigationParameters
+from .sendmail import send_mail
+
+
+__all__ = [
+    "AttachmentUploadHandler",
+    "BodyStructure",
+    "EmailSignature",
+    "ForwardModifier",
+    "IMAPconnector",
+    "ImapEmail",
+    "ReplyModifier",
+    "WebmailNavigationParameters",
+    "clean_attachments",
+    "create_mail_attachment",
+    "decode_payload",
+    "get_imapconnector",
+    "save_attachment",
+    "send_mail",
+    "separate_mailbox",
+    "set_compose_session",
+]
diff --git a/modoboa/webmail/lib/attachments.py b/modoboa/webmail/lib/attachments.py
new file mode 100644
index 000000000..b2649927e
--- /dev/null
+++ b/modoboa/webmail/lib/attachments.py
@@ -0,0 +1,135 @@
+from email import encoders
+from email.mime.base import MIMEBase
+import os
+import uuid
+
+import six
+
+from django.conf import settings
+from django.core.files.uploadhandler import FileUploadHandler, SkipFile
+from django.utils.encoding import smart_bytes
+
+from modoboa.lib.exceptions import InternalError
+from modoboa.lib.web_utils import size2integer
+from modoboa.parameters import tools as param_tools
+
+from .rfc6266 import build_header
+
+
+def get_storage_path(filename):
+    """Return a path to store a file."""
+    storage_dir = os.path.join(settings.MEDIA_ROOT, "webmail")
+    if not filename:
+        return storage_dir
+    return os.path.join(storage_dir, filename)
+
+
+def set_compose_session(request):
+    """Initialize a new "compose" session.
+
+    It is used to keep track of attachments defined with a new
+    message. Each new message will be associated with a unique ID (in
+    order to avoid conflicts between users).
+
+    :param request: a Request object.
+    :return: the new unique ID.
+    """
+    randid = str(uuid.uuid4()).replace("-", "")
+    request.session["compose_mail"] = {"id": randid, "attachments": []}
+    return randid
+
+
+def save_attachment(f):
+    """Save a new attachment to the filesystem.
+
+    The attachment is not saved using its own name to the
+    filesystem. To avoid conflicts, a random name is generated and
+    used instead.
+
+    :param f: an uploaded file object (see Django's documentation) or bytes
+    :return: the new random name
+    """
+    from tempfile import NamedTemporaryFile
+
+    try:
+        fp = NamedTemporaryFile(dir=get_storage_path(""), delete=False)
+    except Exception as e:
+        raise InternalError(str(e)) from None
+    if isinstance(f, (six.binary_type, six.text_type)):
+        fp.write(smart_bytes(f))
+    else:
+        for chunk in f.chunks():
+            fp.write(chunk)
+    fp.close()
+    return fp.name
+
+
+def clean_attachments(attlist):
+    """Remove all attachments from the filesystem
+
+    :param attlist: a list of 2-uple. Each element must contain the
+                    following information : (random name, real name).
+    """
+    for att in attlist:
+        fullpath = get_storage_path(att["tmpname"])
+        try:
+            os.remove(fullpath)
+        except OSError:
+            pass
+
+
+def create_mail_attachment(attdef, payload=None):
+    """Create the MIME part corresponding to the given attachment.
+
+    Mandatory keys: 'fname', 'tmpname', 'content-type'
+
+    :param attdef: a dictionary containing the attachment definition
+    :return: a MIMEBase object
+    """
+    if "content-type" in attdef:
+        maintype, subtype = attdef["content-type"].split("/")
+    elif "Content-Type" in attdef:
+        maintype, subtype = attdef["Content-Type"].split("/")
+    else:
+        return None
+    res = MIMEBase(maintype, subtype)
+    if payload is None:
+        path = get_storage_path(attdef["tmpname"])
+        with open(path, "rb") as fp:
+            res.set_payload(fp.read())
+    else:
+        res.set_payload(payload)
+    encoders.encode_base64(res)
+    if isinstance(attdef["fname"], six.binary_type):
+        attdef["fname"] = attdef["fname"].decode("utf-8")
+    content_disposition = build_header(attdef["fname"])
+    if isinstance(content_disposition, six.binary_type):
+        res["Content-Disposition"] = content_disposition.decode("utf-8")
+    else:
+        res["Content-Disposition"] = content_disposition
+    return res
+
+
+class AttachmentUploadHandler(FileUploadHandler):
+    """
+    Simple upload handler to limit the size of the attachments users
+    can upload.
+    """
+
+    def __init__(self, request=None):
+        super().__init__(request)
+        self.total_upload = 0
+        self.toobig = False
+        self.maxsize = size2integer(
+            param_tools.get_global_parameter("max_attachment_size")
+        )
+
+    def receive_data_chunk(self, raw_data, start):
+        self.total_upload += len(raw_data)
+        if self.total_upload >= self.maxsize:
+            self.toobig = True
+            raise SkipFile()
+        return raw_data
+
+    def file_complete(self, file_size):
+        return None
diff --git a/modoboa/webmail/lib/fetch_parser.py b/modoboa/webmail/lib/fetch_parser.py
new file mode 100644
index 000000000..bbb901d5d
--- /dev/null
+++ b/modoboa/webmail/lib/fetch_parser.py
@@ -0,0 +1,286 @@
+"""Simple parser for FETCH responses.
+
+The ``imaplib`` module doesn't parse IMAP responses, it returns raw
+values. Since Modoboa relies on BODYSTRUCTURE attributes to display
+messages (we don't want to overload the server), a parser is required.
+
+Python 2/3 compatibility note: this parser excepts bytes objects when
+run with Python3 and str (not unicode) ones with Python2.
+"""
+
+import re
+
+import chardet
+import six
+
+
+class ParseError(Exception):
+    """Generic parsing error."""
+
+    pass
+
+
+class Lexer:
+    """The lexical analysis part.
+
+    This class provides a simple way to define tokens (with patterns)
+    to be detected. Patterns are provided using a list of 2-uple. Each
+    2-uple consists of a token name and an associated pattern.
+
+    Example: [("left_bracket", r'\['),]
+    """
+
+    def __init__(self, definitions):
+        self.definitions = definitions
+        parts = []
+        for name, part in definitions:
+            parts.append(rf"(?P<{name}>{part})")
+        self.regexpString = "|".join(parts)
+        self.regexp = re.compile(self.regexpString, re.MULTILINE)
+        self.wsregexp = re.compile(r"\s+", re.M)
+
+    def curlineno(self):
+        """Return the current line number"""
+        return self.text[: self.pos].count("\n") + 1
+
+    def scan(self, text):
+        """Analyze some data.
+
+        Analyse the passed content. Each time a token is recognized, a
+        2-uple containing its name and the parsed value is raised
+        (using yield).
+
+        :param text: a string containing the data to parse
+        :raises: ParseError
+        """
+        self.pos = 0
+        self.text = text
+        while self.pos < len(text):
+            m = self.wsregexp.match(text, self.pos)
+            if m is not None:
+                self.pos = m.end()
+                continue
+
+            m = self.regexp.match(text, self.pos)
+            if m is None:
+                raise ParseError(f"unknown token {text[self.pos :]}")
+
+            self.pos = m.end()
+            yield (m.lastgroup, m.group(m.lastgroup))
+
+
+class FetchResponseParser:
+    """A token generator.
+
+    By *token*, I mean: *literal*, *quoted* or anything else until the
+    next ' ' or ')' character (number, NIL and others should fall into
+    this last category).
+    """
+
+    rules = [
+        ("left_parenthesis", r"\("),
+        ("right_parenthesis", r"\)"),
+        ("string", r'"([^"\\]|\\.)*"'),
+        ("nil", r"NIL"),
+        (
+            "data_item",
+            r"(?P<name>[A-Z][A-Z\.0-9]+)"
+            r"(?P<section>\[.*\])?(?P<origin_octet>\<\d+\>)?",
+        ),
+        ("number", r"[0-9]+"),
+        ("literal_marker", r"{\d+}"),
+        ("flag", r"(\\|\$)?[a-zA-Z0-9\-_]+"),
+    ]
+
+    def __init__(self):
+        """Constructor."""
+        self.lexer = Lexer(self.rules)
+        self.__reset_parser()
+
+    def __reset_parser(self):
+        """Reset parser states."""
+        self.result = {}
+        self.__current_message = {}
+        self.__next_literal_len = 0
+        self.__cur_data_item = None
+        self.__args_parsing_func = None
+        self.__expected = None
+        self.__depth = 0
+        self.__bs_stack = []
+
+    def set_expected(self, *args):
+        """Indicate next expected token types."""
+        self.__expected = args
+
+    def __default_args_parser(self, ttype, tvalue):
+        """Default arguments parser."""
+        self.__current_message[self.__cur_data_item] = tvalue
+        self.__args_parsing_func = None
+
+    def __flags_args_parser(self, ttype, tvalue):
+        """FLAGS arguments parser."""
+        if ttype == "left_parenthesis":
+            self.__current_message[self.__cur_data_item] = []
+            self.__depth += 1
+        elif ttype == "flag":
+            self.__current_message[self.__cur_data_item].append(tvalue)
+            self.set_expected("flag", "right_parenthesis")
+        elif ttype == "right_parenthesis":
+            self.__args_parsing_func = None
+            self.__depth -= 1
+        else:
+            raise ParseError(f"Unexpected token found: {ttype}")
+
+    def __set_part_numbers(self, bs, prefix=""):
+        """Set part numbers."""
+        cpt = 1
+        for mp in bs:
+            if isinstance(mp, list):
+                self.__set_part_numbers(mp, prefix)
+            elif isinstance(mp, dict):
+                if isinstance(mp["struct"][0], list):
+                    nprefix = f"{prefix}{cpt}."
+                    self.__set_part_numbers(mp["struct"][0], nprefix)
+                mp["partnum"] = f"{prefix}{cpt}"
+                cpt += 1
+
+    def __bstruct_args_parser(self, ttype, tvalue):
+        """BODYSTRUCTURE arguments parser."""
+        if ttype == "left_parenthesis":
+            self.__bs_stack = [[]] + self.__bs_stack
+            return
+        if ttype == "right_parenthesis":
+            if len(self.__bs_stack) > 1:
+                part = self.__bs_stack.pop(0)
+                # Check if we are parsing a list of mime part or a
+                # list or arguments.
+                condition = len(self.__bs_stack[0]) > 0 and not isinstance(
+                    self.__bs_stack[0][0], dict
+                )
+                if condition:
+                    self.__bs_stack[0].append(part)
+                else:
+                    self.__bs_stack[0].append({"struct": part})
+            else:
+                # End of BODYSTRUCTURE
+                if not isinstance(self.__bs_stack[0][0], list):
+                    # Special case for non multipart structures
+                    self.__bs_stack[0] = {"struct": self.__bs_stack[0]}
+                self.__set_part_numbers(self.__bs_stack)
+                self.__current_message[self.__cur_data_item] = self.__bs_stack
+                self.__bs_stack = []
+                self.__args_parsing_func = None
+            return
+        if ttype == "string":
+            tvalue = tvalue.strip('"')
+            # Check if previous element was a mime part. If so, we are
+            # dealing with a 'multipart' mime part...
+            condition = len(self.__bs_stack[0]) and isinstance(
+                self.__bs_stack[0][-1], dict
+            )
+            if condition:
+                self.__bs_stack[0] = [self.__bs_stack[0]] + [tvalue]
+                return
+        elif ttype == "number":
+            tvalue = int(tvalue)
+        self.__bs_stack[0].append(tvalue)
+
+    def __parse_data_item(self, ttype, tvalue):
+        """Find next data item."""
+        if ttype == "data_item":
+            self.__cur_data_item = tvalue
+            if tvalue == "BODYSTRUCTURE":
+                self.set_expected("left_parenthesis")
+                self.__args_parsing_func = self.__bstruct_args_parser
+            elif tvalue == "FLAGS":
+                self.set_expected("left_parenthesis")
+                self.__args_parsing_func = self.__flags_args_parser
+            else:
+                self.__args_parsing_func = self.__default_args_parser
+            return
+        elif ttype == "right_parenthesis":
+            self.__depth -= 1
+            assert self.__depth == 0
+            # FIXME: sometimes, FLAGS are returned outside the UID
+            # scope (see sample 1 in tests). For now, we just ignore
+            # them but we need a better solution!
+            if "UID" in self.__current_message:
+                self.result[int(self.__current_message.pop("UID"))] = (
+                    self.__current_message
+                )
+            self.__current_message = {}
+            return
+        raise ParseError(
+            f"unexpected {ttype} found while looking for data_item near {tvalue}"
+        )
+
+    def __convert_to_str(self, chunk):
+        """Convert chunk to str and guess encoding."""
+        condition = (
+            six.PY2
+            and isinstance(chunk, six.text_type)
+            or six.PY3
+            and isinstance(chunk, six.binary_type)
+        )
+        if not condition:
+            return chunk
+        try:
+            chunk = chunk.decode("utf-8")
+        except UnicodeDecodeError:
+            pass
+        else:
+            return chunk
+        try:
+            result = chardet.detect(chunk)
+        except UnicodeDecodeError:
+            raise RuntimeError("Can't find string encoding") from None
+        return chunk.decode(result["encoding"])
+
+    def parse_chunk(self, chunk):
+        """Parse chunk."""
+        if not chunk:
+            return
+        chunk = self.__convert_to_str(chunk)
+        if self.__next_literal_len:
+            literal = chunk[: self.__next_literal_len]
+            chunk = chunk[self.__next_literal_len :]
+            self.__next_literal_len = 0
+            if self.__cur_data_item != "BODYSTRUCTURE":
+                self.__current_message[self.__cur_data_item] = literal
+                self.__args_parsing_func = None
+            else:
+                self.__args_parsing_func("literal", literal)
+        for ttype, tvalue in self.lexer.scan(chunk):
+            if self.__expected is not None:
+                if ttype not in self.__expected:
+                    raise ParseError(
+                        "unexpected {} found while looking for {}".format(
+                            ttype, "|".join(self.__expected)
+                        )
+                    )
+                self.__expected = None
+            if ttype == "literal_marker":
+                self.__next_literal_len = int(tvalue[1:-1])
+                continue
+            elif self.__depth == 0:
+                if ttype == "number":
+                    # We should start here with a message ID
+                    self.set_expected("left_parenthesis")
+                if ttype == "left_parenthesis":
+                    self.__depth += 1
+                continue
+            elif self.__args_parsing_func is None:
+                self.__parse_data_item(ttype, tvalue)
+                continue
+            self.__args_parsing_func(ttype, tvalue)
+
+    def parse(self, data):
+        """Parse received data."""
+        self.__reset_parser()
+        for chunk in data:
+            if isinstance(chunk, tuple):
+                for schunk in chunk:
+                    self.parse_chunk(schunk)
+            else:
+                self.parse_chunk(chunk)
+        return self.result
diff --git a/modoboa/webmail/lib/imapemail.py b/modoboa/webmail/lib/imapemail.py
new file mode 100644
index 000000000..2ad1f109a
--- /dev/null
+++ b/modoboa/webmail/lib/imapemail.py
@@ -0,0 +1,335 @@
+"""
+Set of classes to manipulate/display emails inside the webmail.
+"""
+
+import os
+import re
+import email
+
+import chardet
+import six
+
+from django.conf import settings
+from django.core.files.base import ContentFile
+from django.core.files.storage import default_storage
+from django.urls import reverse
+from django.utils.encoding import smart_str
+from django.utils.html import conditional_escape
+from django.utils.translation import gettext as _
+
+from modoboa.lib import u2u_decode
+from modoboa.lib.email_utils import Email, EmailAddress
+
+from . import imapheader
+from .attachments import get_storage_path
+from .imaputils import get_imapconnector, BodyStructure
+from .utils import decode_payload
+
+
+class ImapEmail(Email):
+    """
+    A class to represent an email fetched from an IMAP server.
+    """
+
+    headernames = [
+        ("From", True),
+        ("To", True),
+        ("Cc", True),
+        ("Date", True),
+        ("Subject", True),
+    ]
+
+    def __init__(self, request, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.request = request
+        self.imapc = get_imapconnector(request)
+        self.mbox, self.mailid = self.mailid.split(":")
+
+    def _insert_contact_links(self, addresses):
+        """Insert 'add to address book' links."""
+        result = []
+        title = _("Add to contacts")
+        url = reverse("api:contact-list")
+        link_tpl = (
+            " <a class='addcontact' href='{}' title='{}'>"
+            "<span class='fa fa-vcard'></span></a>"
+        )
+        for address in addresses:
+            address += link_tpl.format(url, title)
+            result.append(address)
+        return result
+
+    def fetch_headers(self, raw_addresses: bool = False) -> None:
+        """Fetch message headers from server."""
+        msg = self.imapc.fetchmail(
+            self.mbox, self.mailid, readonly=False, what=" ".join(self.headers_as_list)
+        )
+        headers = msg[f"BODY[HEADER.FIELDS ({self.headers_as_text})]"]
+        self.fetch_body_structure(msg)
+        msg = email.message_from_string(headers)
+        for hdr in self.headernames:
+            label = hdr[0]
+            hdrvalue = self.get_header(msg, label, raw=raw_addresses)
+            if not hdrvalue:
+                continue
+            if hdr[1]:
+                self.headers += [{"name": label, "value": hdrvalue}]
+            label = re.sub("-", "_", label)
+            setattr(self, label, hdrvalue)
+
+    def get_header(self, msg, header: str, **kwargs):
+        """Look for a particular header.
+
+        We also try to decode the default value.
+        """
+        hdrvalue = super().get_header(msg, header)
+        if header in ["From", "Reply-To"]:
+            # Store a raw copy for further use
+            setattr(self, f"original_{header.replace('-', '')}", hdrvalue)
+        if not hdrvalue:
+            return ""
+        try:
+            key = re.sub("-", "_", header).lower()
+            hdrvalue = getattr(imapheader, f"parse_{key}")(hdrvalue)
+        except AttributeError:
+            pass
+        return hdrvalue
+
+    def fetch_body_structure(self, msg=None):
+        """Fetch BODYSTRUCTURE for email."""
+        if msg is None:
+            msg = self.imapc.fetchmail(self.mbox, self.mailid, readonly=False)
+        self.bs = BodyStructure(msg["BODYSTRUCTURE"])
+        self._find_attachments()
+        if self.dformat not in ["plain", "html"]:
+            self.dformat = self.request.user.parameters.get_value(self.dformat)
+        fallback_fmt = "html" if self.dformat == "plain" else "plain"
+        self.mformat = (
+            self.dformat if self.dformat in self.bs.contents else fallback_fmt
+        )
+
+    @property
+    def headers_as_list(self):
+        return [hdr[0].upper() for hdr in self.headernames]
+
+    @property
+    def headers_as_text(self):
+        return " ".join(self.headers_as_list)
+
+    @property
+    def body(self):
+        """Load email's body.
+
+        This operation has to be made "on demand" because it requires
+        a communication with the IMAP server.
+        """
+        if self._body is None:
+            self.fetch_body_structure()
+            bodyc = ""
+            parts = self.bs.contents.get(self.mformat, [])
+            for part in parts:
+                pnum = part["pnum"]
+                data = self.imapc._cmd("FETCH", self.mailid, f"(BODY.PEEK[{pnum}])")
+                if not data or int(self.mailid) not in data:
+                    continue
+                content = decode_payload(
+                    part["encoding"], data[int(self.mailid)][f"BODY[{pnum}]"]
+                )
+                if not isinstance(content, six.text_type):
+                    charset = self._find_content_charset(part)
+                    if charset is not None:
+                        try:
+                            content = content.decode(charset)
+                        except (UnicodeDecodeError, LookupError):
+                            result = chardet.detect(content)
+                            content = content.decode(result["encoding"])
+                bodyc += content
+            self._fetch_inlines()
+            if len(bodyc) != 0:
+                bodyc = getattr(self, f"_post_process_{self.mformat}")(bodyc)
+                self._body = getattr(self, f"viewmail_{self.mformat}")(
+                    bodyc, links=self.links
+                )
+        return self._body
+
+    @body.setter
+    def body(self, value):
+        self._body = value
+
+    @property
+    def source(self):
+        """Retrieve email source."""
+        return self.imapc.fetchmail(self.mbox, self.mailid, what="source")["BODY[]"]
+
+    def _find_content_charset(self, part):
+        for pos, elem in enumerate(part["params"]):
+            if elem == "charset":
+                return part["params"][pos + 1]
+        return None
+
+    def _find_attachments(self):
+        """Retrieve attachments from the parsed body structure.
+
+        We try to find and decode a file name for each attachment. If
+        we failed, a generic name will be used (ie. part_1, part_2, ...).
+        """
+        for att in self.bs.attachments:
+            attname = "part_{}".format(att["pnum"])
+            if "params" in att and att["params"] != "NIL":
+                for pos, value in enumerate(att["params"]):
+                    if not value.startswith("name"):
+                        continue
+                    attname = u2u_decode.u2u_decode(att["params"][pos + 1]).strip(
+                        "\r\t\n"
+                    )
+                    break
+            elif "disposition" in att and len(att["disposition"]) > 1:
+                for pos, value in enumerate(att["disposition"][1]):
+                    if not value.startswith("filename"):
+                        continue
+                    attname = u2u_decode.u2u_decode(
+                        att["disposition"][1][pos + 1]
+                    ).strip("\r\t\n")
+                    break
+            self.attachments[att["pnum"]] = smart_str(attname)
+
+    def _fetch_inlines(self):
+        """Store inline images on filesystem to display them."""
+        for cid, params in list(self.bs.inlines.items()):
+            if re.search(r"\.\.", cid):
+                continue
+            fname = f"{self.mailid}_{cid}"
+            path = get_storage_path(fname)
+            params["fname"] = os.path.join(
+                settings.MEDIA_URL, os.path.basename(get_storage_path("")), fname
+            )
+            if default_storage.exists(path):
+                continue
+            pdef, content = self.imapc.fetchpart(self.mailid, self.mbox, params["pnum"])
+            default_storage.save(
+                path, ContentFile(decode_payload(params["encoding"], content))
+            )
+
+    def _map_cid(self, url):
+        m = re.match(".*cid:(.+)", url)
+        if m:
+            if m.group(1) in self.bs.inlines:
+                return self.bs.inlines[m.group(1)]["fname"]
+        return url
+
+    def fetch_attachment(self, pnum):
+        """Fetch an attachment from the IMAP server."""
+        return self.imapc.fetchpart(self.mailid, self.mbox, pnum)
+
+
+class Modifier(ImapEmail):
+    """Message modifier."""
+
+    def __init__(self, form, request, *args, **kwargs):
+        kwargs["dformat"] = request.user.parameters.get_value("editor")
+        super().__init__(request, *args, **kwargs)
+        self.form = form
+        self.fetch_headers(raw_addresses=True)
+        getattr(self, f"_modify_{self.dformat}")()
+
+    def _modify_plain(self):
+        self.body = re.sub("</?pre>", "", self.body)
+
+    def _modify_html(self):
+        if self.dformat == "html" and self.mformat != self.dformat:
+            self.body = re.sub("</?pre>", "", self.body)
+            self.body = re.sub("\n", "<br>", self.body)
+
+    @property
+    def subject(self):
+        """Just a shortcut to return a subject in any case."""
+        return self.Subject if hasattr(self, "Subject") else ""
+
+
+class ReplyModifier(Modifier):
+    """Modify a message to reply to it."""
+
+    headernames = ImapEmail.headernames + [("Reply-To", True), ("Message-ID", False)]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.textheader = f"{self.Form} {_('wrote:')}"
+        if self.dformat == "html":
+            self.textheader = f"<p>{self.textheader}</p>"
+        if hasattr(self, "Message_ID"):
+            self.form.fields["origmsgid"].initial = self.Message_ID
+        if not hasattr(self, "Reply_To"):
+            self.form.fields["to"].initial = self.original_From
+        else:
+            self.form.fields["to"].initial = self.original_ReplyTo
+        if self.request.GET.get("all", "0") == "1":  # reply-all
+            self.form.fields["cc"].initial = ""
+            toparse = self.To.split(",")
+            if hasattr(self, "Cc"):
+                toparse += self.Cc.split(",")
+            for addr in toparse:
+                tmp = EmailAddress(addr)
+                if tmp.address and tmp.address == self.request.user.username:
+                    continue
+                if self.form.fields["cc"].initial != "":
+                    self.form.fields["cc"].initial += ", "
+                self.form.fields["cc"].initial += tmp.fulladdress
+        m = re.match(r"re\s*:\s*.+", self.subject.lower())
+        if m:
+            self.form.fields["subject"].initial = self.subject
+        else:
+            self.form.fields["subject"].initial = f"Re: {self.subject}"
+
+    def _modify_plain(self):
+        super()._modify_plain()
+        lines = self.body.split("\n")
+        body = ""
+        for line in lines:
+            if body != "":
+                body += "\n"
+            body += f">{line}"
+        self.body = body
+
+
+class ForwardModifier(Modifier):
+    """Modify a message so it can be forwarded."""
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._header()
+        self.form.fields["subject"].initial = f"Fwd: {self.subject}"
+
+    def __getfunc(self, name):
+        return getattr(self, f"{name}_{self.dformat}")
+
+    def _header(self):
+        self.textheader = "{}\n".format(self.__getfunc("_header_begin")())
+        self.textheader += self.__getfunc("_header_line")(_("Subject"), self.subject)
+        self.textheader += self.__getfunc("_header_line")(_("Date"), self.Date)
+        for hdr in ["From", "To", "Reply-To"]:
+            try:
+                key = re.sub("-", "_", hdr)
+                value = getattr(self, key)
+                self.textheader += self.__getfunc("_header_line")(_(hdr), value)
+            except AttributeError:
+                pass
+        self.textheader += self.__getfunc("_header_end")()
+
+    def _header_begin_plain(self):
+        return f"----- {_('Original message')} -----"
+
+    def _header_begin_html(self):
+        return f"----- {_('Original message')} -----"
+
+    def _header_line_plain(self, key, value):
+        return f"{key}: {value}\n"
+
+    def _header_line_html(self, key, value):
+        return f"<p>{key}: {conditional_escape(value)}</p>"
+
+    def _header_end_plain(self):
+        return "\n"
+
+    def _header_end_html(self):
+        return ""
diff --git a/modoboa/webmail/lib/imapheader.py b/modoboa/webmail/lib/imapheader.py
new file mode 100644
index 000000000..987981d4b
--- /dev/null
+++ b/modoboa/webmail/lib/imapheader.py
@@ -0,0 +1,139 @@
+"""Set of functions used to parse and transform email headers."""
+
+import datetime
+import email
+
+import chardet
+import six
+
+from django.utils import timezone
+from django.utils.formats import date_format
+
+from modoboa.lib.email_utils import EmailAddress
+from modoboa.lib.signals import get_request
+
+
+__all__ = [
+    "parse_from",
+    "parse_to",
+    "parse_message_id",
+    "parse_date",
+    "parse_reply_to",
+    "parse_cc",
+    "parse_subject",
+]
+
+# date and time formats for email list
+# according to https://en.wikipedia.org/wiki/Date_format_by_country
+# and https://en.wikipedia.org/wiki/Date_and_time_representation_by_country
+DATETIME_FORMATS = {
+    "cs": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "de": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "en": {"SHORT": "l, P", "LONG": "N j, Y P"},
+    "es": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "fr": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "it": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "ja_JP": {"SHORT": "l, P", "LONG": "N j, Y P"},
+    "nl": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "pl_PL": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "pt_PT": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "pt_BR": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "ru": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+    "sv": {"SHORT": "l, H:i", "LONG": "d. N Y H:i"},
+}
+
+
+def to_unicode(value):
+    """Try to convert a string to unicode."""
+    condition = value is None or isinstance(value, six.text_type)
+    if condition:
+        return value
+    try:
+        value = value.decode("utf-8")
+    except UnicodeDecodeError:
+        pass
+    else:
+        return value
+    try:
+        res = chardet.detect(value)
+    except UnicodeDecodeError:
+        return value
+    if res["encoding"] == "ascii":
+        return value
+    return value.decode(res["encoding"])
+
+
+def parse_address(value: str) -> dict:
+    """Parse an email address."""
+    addr = EmailAddress(value)
+    result = {
+        "fulladdress": to_unicode(addr.fulladdress),
+        "address": to_unicode(addr.address),
+    }
+    if addr.name:
+        result["name"] = to_unicode(addr.name)
+    return result
+
+
+def parse_address_list(values: str) -> list[dict]:
+    """Parse a list of email addresses."""
+    lst = values.split(",")
+    result = []
+    for addr in lst:
+        result.append(parse_address(addr))
+    return result
+
+
+def parse_from(value):
+    """Parse a From: header."""
+    return parse_address(value)
+
+
+def parse_to(value):
+    """Parse a To: header."""
+    return parse_address_list(value)
+
+
+def parse_cc(value):
+    """Parse a Cc: header."""
+    return parse_address_list(value)
+
+
+def parse_reply_to(value):
+    """Parse a Reply-To: header."""
+    return parse_address_list(value)
+
+
+def parse_date(value, **kwargs):
+    """Parse a Date: header."""
+    tmp = email.utils.parsedate_tz(value)
+    if not tmp:
+        return value
+    ndate = datetime.datetime.fromtimestamp(email.utils.mktime_tz(tmp))
+    if ndate.tzinfo is not None:
+        tz = timezone.get_current_timezone()
+        ndate = datetime.datetime.fromtimestamp(ndate).replace(tzinfo=tz)
+    current_language = get_request().user.language
+    if datetime.datetime.now() - ndate > datetime.timedelta(7):
+        fmt = "LONG"
+    else:
+        fmt = "SHORT"
+    return date_format(
+        ndate, DATETIME_FORMATS.get(current_language, DATETIME_FORMATS.get("en"))[fmt]
+    )
+
+
+def parse_message_id(value, **kwargs):
+    """Parse a Message-ID: header."""
+    return value.strip("\n")
+
+
+def parse_subject(value, **kwargs):
+    """Parse a Subject: header."""
+    from modoboa.lib import u2u_decode
+
+    try:
+        subject = u2u_decode.u2u_decode(value)
+    except UnicodeDecodeError:
+        subject = value
+    return to_unicode(subject)
diff --git a/modoboa/webmail/lib/imaputils.py b/modoboa/webmail/lib/imaputils.py
new file mode 100644
index 000000000..6f1d09728
--- /dev/null
+++ b/modoboa/webmail/lib/imaputils.py
@@ -0,0 +1,828 @@
+"""Extra IMAPv4 utilities."""
+
+import base64
+import email
+from functools import wraps
+import imaplib
+import re
+import ssl
+import time
+from typing import Optional
+
+from django.conf import settings
+from django.utils.translation import gettext as _
+
+from modoboa.lib import imap_utf7  # noqa
+from modoboa.lib.exceptions import InternalError
+from modoboa.parameters import tools as param_tools
+
+from ..exceptions import ImapError, WebmailInternalError
+from .fetch_parser import FetchResponseParser
+
+imaplib.Debug = 4
+
+# workaround for the "got more than 10000 bytes" exception. MAXLINE
+# value set to 1M, as on latest python versions.
+MAXLINE = 1000000
+if hasattr(imaplib, "_MAXLINE") and imaplib._MAXLINE < MAXLINE:
+    imaplib._MAXLINE = MAXLINE
+
+
+class capability:
+    """
+    Simple decorator to check if the server presents the required
+    capability. If not, a fallback method is called instead.
+
+    :param name: the capability name (upper case)
+    :param fallback_method: a method's name
+    """
+
+    def __init__(self, name: str, fallback_method: str):
+        self.name = name
+        self.fallback_method = fallback_method
+
+    def __call__(self, method):
+        @wraps(method)
+        def wrapped_func(cls, *args, **kwargs):
+            if self.name in cls.capabilities:
+                return method(cls, *args, **kwargs)
+            return getattr(cls, self.fallback_method)(cls, **kwargs)
+
+        return wrapped_func
+
+
+class BodyStructure:
+    """
+    BODYSTRUCTURE response parser.
+
+    Just a simple class that tries to distinguish content parts from
+    attachments.
+    """
+
+    current_mailbox: str
+
+    def __init__(self, definition=None):
+        self.is_multipart = False
+        self.contents = {}
+        self.attachments = []
+        self.inlines = {}
+
+        if definition is not None:
+            self.load_from_definition(definition)
+
+    def __store_part(self, definition: list, pnum: str, multisubtype: str) -> None:
+        """Store the given message part in the appropriate category.
+
+        This method sort parts in two categories:
+
+        * contents (what is going to be displayed)
+        * attachments
+
+        As there is no official definition about what is a content and
+        what is an attachment, the following rules are applied:
+
+        * If the MIME type is text/plain or text/html:
+
+         * If no previous part of this type has already been seen,
+           it's a content
+         * Otherwise it's an attachment
+
+        * Else, if the multipart subtype is related, we consider this
+          part as content because it is certainly an embedded image
+
+        * Any other MIME type is considered as an attachment (for now)
+
+        :param definition: a part definition (list)
+        :param pnum: the part's number
+        :param multisubtype: the multipart subtype
+
+        """
+        pnum = "1" if pnum is None else pnum
+        params = {
+            "pnum": pnum,
+            "params": definition[2],
+            "cid": definition[3],
+            "description": definition[4],
+            "encoding": definition[5],
+            "size": definition[6],
+        }
+        mtype = definition[0].lower()
+        subtype = definition[1].lower()
+        ftype = f"{definition[0].lower()}/{subtype}"
+        if ftype in ("text/plain", "text/html"):
+            if subtype not in self.contents:
+                self.contents[subtype] = [params]
+            else:
+                self.contents[subtype].append(params)
+            return
+        elif multisubtype in ["related"]:
+            self.inlines[params["cid"].strip("<>")] = params
+            return
+
+        params["Content-Type"] = ftype
+        if len(definition) > 7:
+            extensions = ["md5", "disposition", "language", "location"]
+            if mtype == "text":
+                extensions = ["textlines"] + extensions
+            elif ftype == "message/rfc822":
+                extensions = ["envelopestruct", "bodystruct", "textlines"] + extensions
+            for idx, value in enumerate(definition[7:]):
+                params[extensions[idx]] = value
+
+        self.attachments += [params]
+
+    def load_from_definition(
+        self, definition: list, multisubtype: Optional[str] = None
+    ) -> None:
+        for mp in definition:
+            if isinstance(mp, list):
+                if isinstance(mp[0], list):
+                    self.load_from_definition(mp, mp[1])
+                else:
+                    self.load_from_definition(mp)
+            elif isinstance(mp, dict):
+                if isinstance(mp["struct"][0], list):
+                    self.load_from_definition(mp["struct"][0], mp["struct"][1])
+                    continue
+                self.__store_part(mp["struct"], mp["partnum"], multisubtype)
+
+    def has_attachments(self) -> int:
+        return len(self.attachments)
+
+    def find_attachment(self, pnum):
+        for att in self.attachments:
+            if pnum == att["pnum"]:
+                return att
+        return None
+
+
+class IMAPconnector:
+    """The IMAPv4 connector."""
+
+    namespaces_pattern = re.compile(r"(\(\(.+?\)\)|NIL)")
+    namespace_pattern = re.compile(r'\("(?P<prefix>.*?)" "(?P<delimiter>.+?)"\)')
+    list_base_pattern = r'\((?P<flags>.*?)\) "(?P<delimiter>.*)" "?(?P<name>[^"]*)"?'
+    list_response_pattern_literal = re.compile(
+        r'\((?P<flags>.*?)\) "(?P<delimiter>.*)" \{(?P<namelen>\d+)\}'
+    )
+    list_response_pattern = re.compile(list_base_pattern)
+    listextended_response_pattern = re.compile(
+        list_base_pattern + r"\s*(?P<childinfo>.*)"
+    )
+    unseen_pattern = re.compile(r"[^\(]+\(UNSEEN (\d+)\)")
+
+    def __init__(self, user=None, password=None) -> None:
+        self.__hdelimiter: Optional[str] = None
+        self.__ns_prefixes: dict = {}
+        self.quota_usage: int = -1
+        self.criterions: list = []
+        self.conf = dict(param_tools.get_global_parameters("webmail"))
+        self.address = self.conf["imap_server"]
+        self.port = self.conf["imap_port"]
+        self.login(user, password)
+        self.load_namespaces()
+
+    def _cmd(self, name: str, *args, **kwargs) -> Optional[list]:
+        """IMAP command wrapper.
+
+        To simplify errors handling, this wrapper calls the
+        appropriate method (``uid`` or FIXME) and then check the
+        return code. If an error has occured, an ``ImapError``
+        exception is raised.
+
+        For specific commands commands (FETCH, ...), the result is
+        parsed using the IMAPclient module before being returned.
+
+        :param name: the command's name
+        :return: the command's result
+        """
+        if name in ["FETCH", "SORT", "STORE", "COPY", "SEARCH"]:
+            try:
+                typ, data = self.m.uid(name, *args)
+            except imaplib.IMAP4.error as e:
+                raise ImapError(e) from None
+            if typ == "NO":
+                raise ImapError(data)
+            if name == "FETCH":
+                return FetchResponseParser().parse(data)
+            return data
+
+        try:
+            typ, data = self.m._simple_command(name, *args)
+        except imaplib.IMAP4.error as e:
+            raise ImapError(e) from None
+        if typ == "NO":
+            raise ImapError(data)
+        if "responses" not in kwargs:
+            if name not in self.m.untagged_responses:
+                return None
+            return self.m.untagged_responses.pop(name)
+        res = []
+        for r in kwargs["responses"]:
+            if r not in self.m.untagged_responses:
+                return None
+            res.append(self.m.untagged_responses.pop(r))
+        return res
+
+    @property
+    def hdelimiter(self):
+        """Return the default hierachy delimiter.
+
+        :return: a string
+        """
+        if self.__hdelimiter is None:
+            raise InternalError(_("Failed to retrieve hierarchy delimiter"))
+        return self.__hdelimiter
+
+    def login(self, user: str, rawtoken: str) -> None:
+        """Custom login method
+
+        We connect to the server, issue a LOGIN command. If
+        successfull, we try to record a eventuel CAPABILITY untagged
+        response. Otherwise, we issue the command.
+
+        :param user: username
+        :param passwd: password
+        """
+        try:
+            if self.conf["imap_secured"]:
+                self.m = imaplib.IMAP4_SSL(self.address, self.port)
+            else:
+                self.m = imaplib.IMAP4(self.address, self.port)
+        except (OSError, imaplib.IMAP4.error, ssl.SSLError) as error:
+            raise ImapError(_(f"Connection to IMAP server failed: {error}")) from None
+
+        if not settings.WEBMAIL_DEV_MODE:
+            token = (
+                b"n,a="
+                + user.encode("utf-8")
+                + b",\001auth=Bearer "
+                + rawtoken.encode("utf-8")
+                + b"\001\001"
+            )
+            token = base64.b64encode(token)
+            data = self._cmd("AUTHENTICATE", b"OAUTHBEARER", token)
+        else:
+            user = bytes(settings.WEBMAIL_DEV_USERNAME, "utf-8")
+            passwd = bytes(self.m._quote(settings.WEBMAIL_DEV_PASSWORD), "utf-8")
+            data = self._cmd("LOGIN", user, passwd)
+        self.m.state = "AUTH"
+        if "CAPABILITY" in self.m.untagged_responses:
+            self.capabilities = (
+                self.m.untagged_responses.pop("CAPABILITY")[0].decode().split()
+            )
+        else:
+            data = self._cmd("CAPABILITY")
+            self.capabilities = data[0].decode().split()
+
+    def logout(self) -> None:
+        """Logout from server."""
+        try:
+            self._cmd("CHECK")
+        except ImapError:
+            pass
+        self._cmd("LOGOUT")
+        del self.m
+        self.m = None
+        if hasattr(self, "current_mailbox"):
+            del self.current_mailbox
+
+    def load_namespaces(self) -> None:
+        """Load available namespaces."""
+        data = self._cmd("NAMESPACE")
+        nslist = self.namespaces_pattern.findall(data[0].decode())
+        for pos, item in enumerate(["personal", "others", "public"]):
+            if nslist[pos] == "NIL":
+                continue
+            ns = nslist[pos][1:-1]
+            for m in self.namespace_pattern.finditer(ns):
+                if self.__hdelimiter is None:
+                    self.__hdelimiter = m.group("delimiter")
+                if item not in self.__ns_prefixes:
+                    self.__ns_prefixes[item] = []
+                self.__ns_prefixes[item].append(m.group("prefix"))
+
+    def parse_search_parameters(self, criterion: str, pattern: str) -> None:
+        """Parse search information and apply them."""
+
+        def or_criterion(old, c):
+            if old == "":
+                return c
+            return f"OR {old} {c}"
+
+        if criterion == "both":
+            criterion = "from_addr, subject"
+        criterions = ""
+        for c in criterion.split(","):
+            if c == "from_addr":
+                key = "FROM"
+            elif c == "subject":
+                key = "SUBJECT"
+            else:
+                continue
+            criterions = or_criterion(criterions, f"({key} {pattern})")
+        self.criterions = [bytearray(criterions, "utf-8")]
+
+    def messages_count(self, **kwargs) -> int:
+        """An enhanced version of messages_count.
+
+        With IMAP, to know how many messages a mailbox contains, we
+        have to make a request to the server. To avoid requests
+        multiplications, we sort messages in the same time. This will
+        be usefull for other methods.
+
+        :param order: sorting order
+        :param folder: mailbox to scan
+        """
+        if "order" in kwargs and kwargs["order"]:
+            sign = kwargs["order"][:1]
+            criterion = kwargs["order"][1:].upper()
+            if sign == "-":
+                criterion = f"REVERSE {criterion}"
+        else:
+            criterion = "REVERSE DATE"
+        mbox = kwargs.get("mbox")
+
+        # FIXME: pourquoi suis je obligé de faire un SELECT ici?  un
+        # EXAMINE plante mais je pense que c'est du à une mauvaise
+        # lecture des réponses de ma part...
+        self.select_mailbox(mbox, readonly=False)
+        cmdname = "SORT"
+        data = self._cmd(
+            cmdname,
+            bytearray(f"({criterion})", "utf-8"),
+            b"UTF-8",
+            b"(NOT DELETED)",
+            *self.criterions,
+        )
+        self.messages = data[0].decode().split()
+        self.getquota(mbox)
+        return len(self.messages)
+
+    def select_mailbox(
+        self, name: str, readonly: bool = True, force: bool = False
+    ) -> None:
+        """Issue a SELECT/EXAMINE command to the server.
+
+        The given name is first 'imap-utf7' encoded.
+
+        :param name: mailbox's name
+        :param readonly:
+        """
+        if hasattr(self, "current_mailbox"):
+            if self.current_mailbox == name and not force:
+                return
+        self.current_mailbox = name
+        name = self._encode_mbox_name(name)
+        if readonly:
+            self._cmd("EXAMINE", name)
+        else:
+            self._cmd("SELECT", name)
+        self.m.state = "SELECTED"
+
+    def unseen_messages(self, mailbox: str) -> int:
+        """Return the number of unseen messages
+
+        :param mailbox: the mailbox's name
+        :return: an integer
+        """
+        data = self._cmd("STATUS", self._encode_mbox_name(mailbox), "(UNSEEN)")
+        m = self.unseen_pattern.match(data[-1].decode())
+        if m is None:
+            return 0
+        return int(m.group(1))
+
+    def _encode_mbox_name(self, folder):
+        """Encode folder name (str) to imap4-utf-7 and quote it."""
+        if not folder:
+            return "INBOX"
+        return b'"' + folder.encode("imap4-utf-7") + b'"'
+
+    def _parse_mailbox_name(self, descr, prefix, delimiter, parts):
+        if not len(parts):
+            return False
+        path = f"{prefix}{delimiter}{parts[0]}"
+        sdescr = None
+        for d in descr:
+            if d["path"] == path:
+                sdescr = d
+                break
+        if sdescr is None:
+            sdescr = {"name": parts[0], "path": path, "sub": []}
+            descr += [sdescr]
+        if self._parse_mailbox_name(sdescr["sub"], path, delimiter, parts[1:]):
+            sdescr["class"] = "subfolders"
+        return True
+
+    def _listmboxes_simple(
+        self, topmailbox: str = "INBOX", mailboxes: Optional[list] = None, **kwargs
+    ) -> None:
+        # data = self._cmd("LIST", "", "*")
+        if not mailboxes:
+            mailboxes = []
+        (status, data) = self.m.list()
+        newmboxes = []
+        for mb in data:
+            flags, delimiter, name = self.list_response_pattern.match(
+                mb.decode()
+            ).groups()
+            name = bytearray(name.strip('"'), "utf-8").decode("imap4-utf-7")
+            mdm_found = False
+            for idx, mdm in enumerate(mailboxes):
+                if mdm["name"] == name:
+                    mdm_found = True
+                    descr = mailboxes[idx]
+                    break
+            if not mdm_found:
+                descr = {"name": name}
+                newmboxes += [descr]
+
+            if re.search(rf"\{delimiter}", name):
+                parts = name.split(delimiter)
+                if "path" not in descr:
+                    descr["path"] = parts[0]
+                    descr["sub"] = []
+                if self._parse_mailbox_name(
+                    descr["sub"], parts[0], delimiter, parts[1:]
+                ):
+                    descr["class"] = "subfolders"
+                continue
+
+        from operator import itemgetter
+
+        mailboxes += sorted(newmboxes, key=itemgetter("name"))
+
+    @capability("LIST-EXTENDED", "_listmboxes_simple")
+    def _listmboxes(self, topmailbox: str, mailboxes: list, until_mailbox=None) -> None:
+        """Retrieve mailboxes list."""
+        pattern = (
+            f'"{topmailbox.encode("imap4-utf-7").decode()}{self.hdelimiter}%"'
+            if topmailbox
+            else "%"
+        )
+        resp = self._cmd(
+            "LIST", '""', pattern, "RETURN", "(CHILDREN STATUS (MESSAGES))"
+        )
+        newmboxes = []
+        for mb in resp:
+            if not mb:
+                continue
+            if type(mb) in [list, tuple]:
+                flags, delimiter, namelen = self.list_response_pattern_literal.match(
+                    mb[0].decode()
+                ).groups()
+                name = mb[1][0 : int(namelen)]
+            else:
+                flags, delimiter, name, childinfo = (
+                    self.listextended_response_pattern.match(mb.decode()).groups()
+                )
+            flags = flags.split(" ")
+            name = bytearray(name, "utf-8")
+            name = name.decode("imap4-utf-7")
+            mdm_found = False
+            for idx, mdm in enumerate(mailboxes):
+                if mdm["name"] == name:
+                    mdm_found = True
+                    descr = mailboxes[idx]
+                    break
+            if not mdm_found:
+                descr = {"name": name, "label": name, "type": "normal"}
+                newmboxes += [descr]
+
+            if "\\Marked" in flags or "\\UnMarked" not in flags:
+                descr["send_status"] = True
+            if r"\NonExistent" in flags:
+                descr["removed"] = True
+            if "\\HasChildren" in flags:
+                descr["path"] = name
+                descr["sub"] = []
+                if until_mailbox and until_mailbox.startswith(name):
+                    self._listmboxes(name, descr["sub"], until_mailbox)
+
+        from operator import itemgetter
+
+        mailboxes += sorted(newmboxes, key=itemgetter("name"))
+
+    def getmboxes(
+        self,
+        user,
+        topmailbox: str = "",
+        until_mailbox=None,
+        unseen_messages: bool = True,
+    ) -> list:
+        """Returns a list of mailboxes for a particular user.
+
+        By default, only the first level of mailboxes under
+        ``topmailbox`` is returned. If ``until_mailbox`` is specified,
+        all levels needed to access this mailbox will be returned.
+
+        :param user: a ``User`` instance
+        :param topmailbox: the mailbox where to start in the tree
+        :param until_mailbox: the deepest needed mailbox
+        :param unseen_messages: include unseen messages counters or not
+        :return: a list
+        """
+        if topmailbox:
+            md_mailboxes = []
+        else:
+            md_mailboxes = [
+                {"name": "INBOX", "type": "inbox", "label": _("Inbox")},
+                {
+                    "name": user.parameters.get_value("drafts_folder"),
+                    "type": "draft",
+                    "label": _("Drafts"),
+                },
+                {
+                    "name": user.parameters.get_value("junk_folder"),
+                    "type": "junk",
+                    "label": _("Junk"),
+                },
+                {
+                    "name": user.parameters.get_value("sent_folder"),
+                    "type": "sent",
+                    "label": _("Sent"),
+                },
+                {
+                    "name": user.parameters.get_value("trash_folder"),
+                    "type": "trash",
+                    "label": _("Trash"),
+                },
+            ]
+        if until_mailbox:
+            name, parent = separate_mailbox(until_mailbox, self.hdelimiter)
+            if parent:
+                until_mailbox = parent
+        self._listmboxes(topmailbox, md_mailboxes, until_mailbox)
+
+        if unseen_messages:
+            for mb in md_mailboxes:
+                if "send_status" not in mb:
+                    continue
+                del mb["send_status"]
+                key = "path" if "path" in mb else "name"
+                if mb.get("removed", False):
+                    continue
+                count = self.unseen_messages(mb[key])
+                if count == 0:
+                    continue
+                mb["unseen"] = count
+        return md_mailboxes
+
+    def _add_flag(self, mbox: str, msgset, flag: str) -> None:
+        """Add flag to a messages set.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        :param flag: the flag to add
+        """
+        self.select_mailbox(mbox, False)
+        self._cmd("STORE", msgset, "+FLAGS", flag)
+
+    def _remove_flag(self, mbox: str, msgset, flag: str) -> None:
+        """Remove flag from a message set.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        :param flag: the flag to remove
+        """
+        self.select_mailbox(mbox, False)
+        self._cmd("STORE", msgset, "-FLAGS", flag)
+
+    def mark_messages_unread(self, mbox: str, msgset) -> None:
+        """Mark a set of messages as unread.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        """
+        self._remove_flag(mbox, msgset, r"(\Seen)")
+
+    def mark_messages_read(self, mbox: str, msgset) -> None:
+        """Mark a set of messages as unread.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        """
+        self._add_flag(mbox, msgset, r"(\Seen)")
+
+    def mark_messages_flagged(self, mbox: str, msgset) -> None:
+        """Mark a set of messages as flagged.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        """
+        self._add_flag(mbox, msgset, r"(\Flagged)")
+
+    def mark_messages_unflagged(self, mbox: str, msgset) -> None:
+        """Mark a set of messages as unflagged.
+
+        :param mbox: the mailbox containing the messages
+        :param msgset: messages set (uid)
+        """
+        self._remove_flag(mbox, msgset, r"(\Flagged)")
+
+    def msg_forwarded(self, mailbox: str, mailid: str) -> None:
+        self._add_flag(mailbox, mailid, "($Forwarded)")
+
+    def msg_answered(self, mailbox: str, mailid: str) -> None:
+        """Add the \Answered flag to this email."""
+        self._add_flag(mailbox, mailid, r"(\Answered)")
+
+    def move(self, msgset, oldmailbox: str, newmailbox: str) -> None:
+        """Move messages between mailboxes."""
+        self.select_mailbox(oldmailbox, False)
+        self._cmd("COPY", msgset, self._encode_mbox_name(newmailbox))
+        self._cmd("STORE", msgset, "+FLAGS", r"(\Deleted \Seen)")
+
+    def push_mail(self, mbox: str, msg):
+        now = imaplib.Time2Internaldate(time.time())
+        msg = bytes(msg)
+        return self.m.append(self._encode_mbox_name(mbox), r"(\Seen)", now, msg)
+
+    def empty(self, mbox: str):
+        self.select_mailbox(mbox, False)
+        resp = self._cmd("SEARCH", "ALL")
+        seq = b",".join(resp[0].split())
+        if seq == b"":
+            return
+        self._cmd("STORE", seq, "+FLAGS", r"(\Deleted)")
+        self._cmd("EXPUNGE")
+
+    def compact(self, mbox: str):
+        """Compact a specific mailbox.
+
+        Issue an EXPUNGE command for the specified mailbox.
+
+        :param mbox: the mailbox's name
+        """
+        self.select_mailbox(mbox, False)
+        self._cmd("EXPUNGE")
+
+    def create_folder(self, name: str, parent: Optional[str] = None) -> bool:
+        if parent is not None:
+            name = f"{parent}{self.hdelimiter}{name}"
+        typ, data = self.m.create(self._encode_mbox_name(name))
+        if typ == "NO":
+            raise WebmailInternalError(data[0])
+        return True
+
+    def rename_folder(self, oldname: str, newname: str) -> bool:
+        typ, data = self.m.rename(
+            self._encode_mbox_name(oldname), self._encode_mbox_name(newname)
+        )
+        if typ == "NO":
+            raise WebmailInternalError(data[0], ajax=True)
+        return True
+
+    def delete_folder(self, name: str) -> bool:
+        typ, data = self.m.delete(self._encode_mbox_name(name))
+        if typ == "NO":
+            raise WebmailInternalError(data[0])
+        return True
+
+    def getquota(self, mailbox: str) -> None:
+        """Retrieve quota information from the server.
+
+        We also compute the current usage.
+        """
+        if "QUOTA" not in self.capabilities:
+            self.quota_limit = self.quota_current = None
+            return
+        try:
+            data = self._cmd(
+                "GETQUOTAROOT",
+                self._encode_mbox_name(mailbox),
+                responses=["QUOTAROOT", "QUOTA"],
+            )
+        except ImapError:
+            data = None
+
+        if data is None:
+            self.quota_limit = self.quota_current = None
+            return
+
+        quotadef = data[1][0].decode()
+        m = re.search(r"\(STORAGE (\d+) (\d+)\)", quotadef)
+        if not m:
+            print("Problem while parsing quota def")
+            return
+        self.quota_limit = int(m.group(2))
+        self.quota_current = int(m.group(1))
+        try:
+            self.quota_usage = int(
+                float(self.quota_current) / float(self.quota_limit) * 100
+            )
+        except TypeError:
+            self.quota_usage = -1
+
+    def fetchpart(self, uid: str, mbox: str, partnum):
+        """Retrieve a specific message part.
+
+        Useful to fetch attachments from the server. Part headers and
+        the payload are returned separatly.
+
+        :param uid: a message UID
+        :param mbox: the mailbox containing the message
+        :param partnum: the part number
+        :return: a 2uple (dict, string)
+        """
+        self.select_mailbox(mbox, False)
+        data = self._cmd("FETCH", uid, f"(BODYSTRUCTURE BODY[{partnum}])")
+        bs = BodyStructure(data[int(uid)]["BODYSTRUCTURE"])
+        attdef = bs.find_attachment(partnum)
+        return attdef, data[int(uid)][f"BODY[{partnum}]"]
+
+    def fetch(
+        self, start: int, stop: Optional[int] = None, mbox: Optional[str] = None
+    ) -> list:
+        """Retrieve information about messages from the server.
+
+        Issue a FETCH command to retrieve information about one or
+        more messages (such as headers) from the server.
+
+        :param start: index of the first message
+        :param stop: index of the last message (optionnal)
+        :param mbox: the mailbox that contains the messages
+        """
+        self.select_mailbox(mbox, False)
+        if start and stop:
+            submessages = self.messages[start - 1 : stop]
+            mrange = ",".join(submessages)
+        else:
+            submessages = [start]
+            mrange = str(start)
+        headers = "DATE FROM TO CC SUBJECT"
+        query = (
+            f"(FLAGS BODYSTRUCTURE RFC822.SIZE BODY.PEEK[HEADER.FIELDS ({headers})])"
+        )
+        data = self._cmd("FETCH", mrange, query)
+        result = []
+        for uid in submessages:
+            msg_data = data[int(uid)]
+            msg = email.message_from_string(
+                msg_data[f"BODY[HEADER.FIELDS ({headers})]"]
+            )
+            print(type(msg))
+            msg["imapid"] = uid
+            msg["size"] = msg_data["RFC822.SIZE"]
+            if r"\Seen" not in msg_data["FLAGS"]:
+                msg["style"] = "unseen"
+            if r"\Answered" in msg_data["FLAGS"]:
+                msg["answered"] = True
+            if r"$Forwarded" in msg_data["FLAGS"]:
+                msg["forwarded"] = True
+            if r"\Flagged" in msg_data["FLAGS"]:
+                msg["flagged"] = True
+            bstruct = BodyStructure(msg_data["BODYSTRUCTURE"])
+            if bstruct.has_attachments():
+                msg["attachments"] = True
+            result += [msg]
+        return result
+
+    def fetchmail(
+        self, mbox: str, mailid: str, readonly: bool = True, what: str = "bodystructure"
+    ):
+        """Retrieve information about a specific message.
+
+        Issue a FETCH command to retrieve a message's content from the
+        server. In order to not overload the server, we first retrieve
+        the BODYSTRUCTURE of the message. Then, according to the
+        result and to the user's preferences, we retrieve the
+        appropriate content (plain, html, etc.).
+
+        :param mbox: the mailbox containing the message
+        :param mailid: the message's unique id
+        :param readonly:
+        :param headers:
+        """
+        self.select_mailbox(mbox, readonly)
+        if what == "bodystructure":
+            to_fetch = "(BODYSTRUCTURE)"
+        elif what == "source":
+            to_fetch = "(BODY[])"
+        else:
+            bcmd = "BODY.PEEK" if readonly else "BODY"
+            to_fetch = f"(BODYSTRUCTURE {bcmd}[HEADER.FIELDS ({what})])"
+        data = self._cmd("FETCH", mailid, to_fetch)
+        return data[int(mailid)]
+
+
+def separate_mailbox(fullname: str, sep: str = ".") -> tuple[str, Optional[str]]:
+    """Split a mailbox name.
+
+    If a separator is found in ``fullname``, this function returns the
+    corresponding name and parent mailbox name.
+    """
+    if sep in fullname:
+        parts = fullname.split(sep)
+        name = parts[-1]
+        parent = sep.join(parts[0 : len(parts) - 1])
+        return name, parent
+    return fullname, None
+
+
+def get_imapconnector(request) -> IMAPconnector:
+    """Shortcut to create an IMAP connector.
+
+    :param request: a ``Request`` object
+    """
+    return IMAPconnector(request.user.username, str(request.auth))
diff --git a/modoboa/webmail/lib/rfc6266.py b/modoboa/webmail/lib/rfc6266.py
new file mode 100644
index 000000000..b79ea2b95
--- /dev/null
+++ b/modoboa/webmail/lib/rfc6266.py
@@ -0,0 +1,108 @@
+"""
+Copy of the original rfc6266 package, just the generation part.
+
+Orginal code is available at https://github.com/g2p/rfc6266.
+"""
+
+from urllib.parse import quote
+
+
+# RFC 2616
+separator_chars = '()<>@,;:\\"/[]?={} \t'
+# RFC 5987
+attr_chars_nonalnum = "!#$&+-.^_`|~"
+
+
+def percent_encode(string, safe, encoding):
+    return quote(string, safe, encoding, errors="strict")
+
+
+def is_token_char(ch):
+    # Must be ascii, and neither a control char nor a separator char
+    asciicode = ord(ch)
+    # < 128 means ascii, exclude control chars at 0-31 and 127,
+    # exclude separator characters.
+    return 31 < asciicode < 127 and ch not in separator_chars
+
+
+def is_token(candidate):
+    return all(is_token_char(ch) for ch in candidate)
+
+
+def is_ascii(text):
+    return all(ord(ch) < 128 for ch in text)
+
+
+def fits_inside_codec(text, codec):
+    try:
+        text.encode(codec)
+    except UnicodeEncodeError:
+        return False
+    else:
+        return True
+
+
+def is_lws_safe(text):
+    return normalize_ws(text) == text
+
+
+def normalize_ws(text):
+    return " ".join(text.split())
+
+
+def qd_quote(text):
+    return text.replace("\\", "\\\\").replace('"', '\\"')
+
+
+def build_header(filename, disposition="attachment", filename_compat=None):
+    """Generate a Content-Disposition header for a given filename.
+    For legacy clients that don't understand the filename* parameter,
+    a filename_compat value may be given.
+    It should either be ascii-only (recommended) or iso-8859-1 only.
+    In the later case it should be a character string
+    (unicode in Python 2).
+    Options for generating filename_compat (only useful for legacy clients):
+    - ignore (will only send filename*);
+    - strip accents using unicode's decomposing normalisations,
+    which can be done from unicode data (stdlib), and keep only ascii;
+    - use the ascii transliteration tables from Unidecode (PyPI);
+    - use iso-8859-1
+    Ignore is the safest, and can be used to trigger a fallback
+    to the document location (which can be percent-encoded utf-8
+    if you control the URLs).
+    See https://tools.ietf.org/html/rfc6266#appendix-D
+    """
+
+    # While this method exists, it could also sanitize the filename
+    # by rejecting slashes or other weirdness that might upset a receiver.
+
+    if disposition != "attachment":
+        assert is_token(disposition)
+
+    rv = disposition
+
+    if is_token(filename):
+        rv += f"; filename={filename}"
+        return rv
+    elif is_ascii(filename) and is_lws_safe(filename):
+        qd_filename = qd_quote(filename)
+        rv += f'; filename="{qd_filename}"'
+        if qd_filename == filename:
+            # RFC 6266 claims some implementations are iffy on qdtext's
+            # backslash-escaping, we'll include filename* in that case.
+            return rv
+    elif filename_compat:
+        if is_token(filename_compat):
+            rv += f"; filename={filename_compat}"
+        else:
+            assert is_lws_safe(filename_compat)
+            rv += f'; filename="{qd_quote(filename_compat)}"'
+
+    # alnum are already considered always-safe, but the rest isn't.
+    # Python encodes ~ when it shouldn't, for example.
+    rv += "; filename*=utf-8''{}".format(
+        percent_encode(filename, safe=attr_chars_nonalnum, encoding="utf-8"),
+    )
+
+    # This will only encode filename_compat, if it used non-ascii iso-8859-1.
+    return rv.encode("iso-8859-1")
diff --git a/modoboa/webmail/lib/sendmail.py b/modoboa/webmail/lib/sendmail.py
new file mode 100644
index 000000000..922fa8555
--- /dev/null
+++ b/modoboa/webmail/lib/sendmail.py
@@ -0,0 +1,66 @@
+import smtplib
+
+from django.core import mail
+from django.template.loader import render_to_string
+
+from modoboa.lib.cryptutils import get_password
+from modoboa.parameters import tools as param_tools
+
+from . import get_imapconnector, clean_attachments
+
+
+def send_mail(request, form, posturl=None):
+    """Email verification and sending.
+
+    If the form does not present any error, a new MIME message is
+    constructed. Then, a connection is established with the defined
+    SMTP server and the message is finally sent.
+
+    :param request: a Request object
+    :param posturl: the url to post the message form to
+    :return: a 2-uple (True|False, HttpResponse)
+    """
+    if not form.is_valid():
+        editormode = request.user.parameters.get_value("editor")
+        listing = render_to_string(
+            "modoboa_webmail/compose.html",
+            {
+                "form": form,
+                "noerrors": True,
+                "body": form.cleaned_data.get("body", "").strip(),
+                "posturl": posturl,
+            },
+            request,
+        )
+        return False, {"status": "ko", "listing": listing, "editor": editormode}
+
+    msg = form.to_msg(request)
+    conf = dict(param_tools.get_global_parameters("modoboa_webmail"))
+    options = {"host": conf["smtp_server"], "port": conf["smtp_port"]}
+    if conf["smtp_secured_mode"] == "ssl":
+        options.update({"use_ssl": True})
+    elif conf["smtp_secured_mode"] == "starttls":
+        options.update({"use_tls": True})
+    if conf["smtp_authentication"]:
+        options.update(
+            {"username": request.user.username, "password": get_password(request)}
+        )
+    try:
+        with mail.get_connection(**options) as connection:
+            msg.connection = connection
+            msg.send()
+    except smtplib.SMTPResponseException as inst:
+        return False, {"status": "ko", "error": inst.smtp_error}
+    except smtplib.SMTPRecipientsRefused as inst:
+        error = ", ".join(
+            [f"{rcpt}: {error}" for rcpt, error in inst.recipients.items()]
+        )
+        return False, {"status": "ko", "error": error}
+
+    # Copy message to sent folder
+    sentfolder = request.user.parameters.get_value("sent_folder")
+    get_imapconnector(request).push_mail(sentfolder, msg.message())
+    clean_attachments(request.session["compose_mail"]["attachments"])
+    del request.session["compose_mail"]
+
+    return True, {}
diff --git a/modoboa/webmail/lib/signature.py b/modoboa/webmail/lib/signature.py
new file mode 100644
index 000000000..2bfe567b5
--- /dev/null
+++ b/modoboa/webmail/lib/signature.py
@@ -0,0 +1,28 @@
+"""Tools to deal with message signatures."""
+
+
+class EmailSignature:
+    """User signature.
+
+    :param user: User object
+    """
+
+    def __init__(self, user):
+        self._sig = ""
+        dformat = user.parameters.get_value("editor")
+        content = user.parameters.get_value("signature")
+        if len(content):
+            getattr(self, f"_format_sig_{dformat}")(content)
+
+    def _format_sig_plain(self, content):
+        self._sig = f"""
+---
+{content}"""
+
+    def _format_sig_html(self, content):
+        content = f"---<br>{content}"
+        self._sig = content
+        return
+
+    def __str__(self):
+        return self._sig
diff --git a/modoboa/webmail/lib/utils.py b/modoboa/webmail/lib/utils.py
new file mode 100644
index 000000000..dbe2105f8
--- /dev/null
+++ b/modoboa/webmail/lib/utils.py
@@ -0,0 +1,22 @@
+"""Misc. utilities."""
+
+
+def decode_payload(encoding, payload):
+    """Decode the payload according to the given encoding
+
+    Supported encodings: base64, quoted-printable.
+
+    :param encoding: the encoding's name
+    :param payload: the value to decode
+    :return: a string
+    """
+    encoding = encoding.lower()
+    if encoding == "base64":
+        import base64
+
+        return base64.b64decode(payload)
+    elif encoding == "quoted-printable":
+        import quopri
+
+        return quopri.decodestring(payload)
+    return payload
diff --git a/modoboa/webmail/serializers.py b/modoboa/webmail/serializers.py
new file mode 100644
index 000000000..9218cfe76
--- /dev/null
+++ b/modoboa/webmail/serializers.py
@@ -0,0 +1,94 @@
+"""Webmail serializers."""
+
+from rest_framework import serializers
+
+from modoboa.webmail import constants
+from modoboa.webmail.lib import imapheader
+
+
+class GlobalParametersSerializer(serializers.Serializer):
+    max_attachment_size = serializers.CharField(default="2048")
+
+    imap_server = serializers.CharField(default="127.0.0.1")
+    imap_secured = serializers.BooleanField(default=False)
+    imap_port = serializers.IntegerField(default=143)
+
+    smtp_server = serializers.CharField(default="127.0.0.1")
+    smtp_secured_mode = serializers.ChoiceField(
+        default=constants.SmtpConnectionMode.NONE.value,
+        choices=constants.SMTP_CONNECTION_MODES,
+    )
+    smtp_port = serializers.IntegerField(default=25)
+    smtp_authentication = serializers.BooleanField(default=False)
+
+
+class UserPreferencesSerializer(serializers.Serializer):
+    displaymode = serializers.ChoiceField(
+        default=constants.DisplayMode.PLAIN.value, choices=constants.DISPLAY_MODES
+    )
+    enable_links = serializers.BooleanField(default=False)
+    messages_per_page = serializers.IntegerField(default=40)
+    refresh_interval = serializers.IntegerField(default=300)
+    mboxes_col_width = serializers.IntegerField(default=200)
+
+    trash_folder = serializers.CharField(default="Trash")
+    sent_folder = serializers.CharField(default="Sent")
+    drafts_folder = serializers.CharField(default="Drafts")
+    junk_folder = serializers.CharField(default="Junk")
+
+    editor = serializers.ChoiceField(
+        default=constants.DisplayMode.PLAIN.value, choices=constants.DISPLAY_MODES
+    )
+    signature = serializers.CharField(required=False)
+
+
+class UserMailboxSerializer(serializers.Serializer):
+
+    name = serializers.CharField()
+    path = serializers.CharField(required=False)
+    label = serializers.CharField()
+    type = serializers.ChoiceField(choices=constants.MAILBOX_TYPES)
+    unseen = serializers.IntegerField(default=0)
+    removed = serializers.BooleanField(default=False)
+    sub = serializers.SerializerMethodField()
+
+    def get_sub(self, obj):
+        if "sub" in obj:
+            return UserMailboxSerializer(obj["sub"], many=True).data
+        return None
+
+
+class EmailAddressSerializer(serializers.Serializer):
+    fulladdress = serializers.CharField()
+    address = serializers.CharField()
+    name = serializers.CharField(required=False)
+
+
+class EmailHeadersSerializer(serializers.Serializer):
+
+    mailid = serializers.CharField()
+    subject = serializers.SerializerMethodField()
+    from_address = serializers.SerializerMethodField()
+    date = serializers.SerializerMethodField()
+    size = serializers.IntegerField()
+    answered = serializers.BooleanField(default=False)
+    attachments = serializers.BooleanField(default=False)
+    forwarded = serializers.BooleanField(default=False)
+    flagged = serializers.BooleanField(default=False)
+    style = serializers.CharField(required=False)
+
+    def get_subject(self, obj) -> str:
+        return imapheader.parse_subject(obj["Subject"])
+
+    def get_from_address(self, obj):
+        return imapheader.parse_address(obj["From"])
+
+    def get_date(self, obj) -> str:
+        return imapheader.parse_date(obj["Date"])
+
+
+class EmailSerializer(serializers.Serializer):
+
+    subject = serializers.CharField(source="Subject")
+    from_address = EmailAddressSerializer(source="From")
+    body = serializers.CharField()
diff --git a/modoboa/webmail/urls.py b/modoboa/webmail/urls.py
new file mode 100644
index 000000000..ba888c56f
--- /dev/null
+++ b/modoboa/webmail/urls.py
@@ -0,0 +1,12 @@
+"""Webmail API urls."""
+
+from rest_framework import routers
+
+from modoboa.webmail import viewsets
+
+
+router = routers.SimpleRouter()
+router.register(r"mailboxes", viewsets.UserMailboxViewSet, basename="webmail-mailbox")
+router.register(r"emails", viewsets.UserEmailViewSet, basename="webmail-email")
+
+urlpatterns = router.urls
diff --git a/modoboa/webmail/viewsets.py b/modoboa/webmail/viewsets.py
new file mode 100644
index 000000000..314490190
--- /dev/null
+++ b/modoboa/webmail/viewsets.py
@@ -0,0 +1,49 @@
+"""Webmail viewsets."""
+
+from django.http import Http404
+
+from rest_framework import response, viewsets
+from rest_framework.decorators import action
+from rest_framework.permissions import IsAuthenticated
+
+from modoboa.lib.paginator import Paginator
+from modoboa.webmail import lib, serializers
+
+
+class UserMailboxViewSet(viewsets.GenericViewSet):
+    permission_classes = (IsAuthenticated,)
+    serializer_class = serializers.UserMailboxSerializer
+
+    def list(self, request):
+        parent_mailbox = request.GET.get("mailbox", "")
+        imapc = lib.get_imapconnector(request)
+        mboxes = imapc.getmboxes(request.user, parent_mailbox)
+        serializer = serializers.UserMailboxSerializer(mboxes, many=True)
+        return response.Response(serializer.data)
+
+
+class UserEmailViewSet(viewsets.GenericViewSet):
+
+    def list(self, request):
+        mailbox = request.GET.get("mailbox", "INBOX")
+        imapc = lib.get_imapconnector(request)
+        paginator = Paginator(
+            imapc.messages_count(mbox=mailbox),
+            request.user.parameters.get_value("messages_per_page"),
+        )
+        page = paginator.getpage(1)
+        content = imapc.fetch(page.id_start, page.id_stop, mbox=mailbox)
+        content = [dict(msg) for msg in content]
+        serializer = serializers.EmailHeadersSerializer(content, many=True)
+        return response.Response(serializer.data)
+
+    @action(methods=["get"], detail=False)
+    def content(self, request):
+        mailbox = request.GET.get("mailbox", "INBOX")
+        mailid = request.GET.get("mailid")
+        if not mailbox or not mailid:
+            raise Http404
+        email = lib.ImapEmail(request, f"{mailbox}:{mailid}")
+        email.fetch_headers()
+        serializer = serializers.EmailSerializer(email)
+        return response.Response(serializer.data)
diff --git a/test_project/test_project/settings.py b/test_project/test_project/settings.py
index d26270a75..dd8e6d3c7 100644
--- a/test_project/test_project/settings.py
+++ b/test_project/test_project/settings.py
@@ -104,6 +104,7 @@ MODOBOA_APPS = (
     # Modoboa extensions here.
     "modoboa.contacts",
     "modoboa.calendars",
+    "modoboa.webmail",
 )
 
 try:
@@ -426,3 +427,7 @@ DISABLE_DASHBOARD_EXTERNAL_QUERIES = False
 # Load settings from extensions
 
 LDAP_SERVER_PORT = os.environ.get("LDAP_SERVER_PORT", 3389)
+
+WEBMAIL_DEV_MODE = True
+WEBMAIL_DEV_USERNAME = os.environ.get("WEBMAIL_DEV_USERNAME", "")
+WEBMAIL_DEV_PASSWORD = os.environ.get("WEBMAIL_DEV_PASSWORD", "")