diff --git a/frontend/src/components/contacts/ContactList.vue b/frontend/src/components/contacts/ContactList.vue
index e24839567..0c42cc60a 100644
--- a/frontend/src/components/contacts/ContactList.vue
+++ b/frontend/src/components/contacts/ContactList.vue
@@ -1,97 +1,120 @@
 <template>
-  <v-card class="mt-6">
-    <v-data-table :headers="headers" :items="contacts">
-      <template #top>
-        <v-toolbar color="white" flat>
-          <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-btn color="primary" variant="outlined" @click="showForm = true">
-            {{ $gettext('Add') }}
-          </v-btn>
-          <template v-if="preferences.enable_carddav_sync">
-            <v-btn
-              icon="mdi-information-outline"
-              :title="$gettext('Display address book information')"
-              class="ml-2"
-              @click="showAddressBookInfo = true"
-            />
-            <v-btn
-              v-if="!addressBook.last_sync"
-              icon="mdi-sync"
-              color="success"
-              :title="$gettext('Synchronize contacts with address book')"
-              @click="syncToAddressBook"
-            />
-          </template>
-          <v-chip
-            v-if="$route.params.category"
-            class="my-2 mx-4"
-            label
-            size="small"
-            color="green"
-            prepend-icon="mdi-label"
-            @click="editCategory"
-          >
-            {{ $route.params.category }}
-          </v-chip>
-          <v-spacer></v-spacer>
-        </v-toolbar>
-      </template>
-      <template #[`item.display_name`]="{ item }">
-        <template v-if="item.display_name">
-          {{ item.display_name }}
-        </template>
-        <template v-else> {{ item.first_name }} {{ item.last_name }} </template>
-      </template>
-      <template #[`item.emails`]="{ item }">
-        {{ displayEmails(item.emails) }}
-      </template>
-      <template #[`item.phone_numbers`]="{ item }">
-        {{ displayPhoneNumbers(item.phone_numbers) }}
-      </template>
-      <template #[`item.actions`]="{ item }">
-        <div class="text-right">
-          <v-menu offset-y>
-            <template #activator="{ props }">
-              <v-btn icon="mdi-dots-horizontal" variant="text" v-bind="props">
+  <div>
+    <v-card class="mt-6">
+      <v-data-table :headers="headers" :items="contacts">
+        <template #top>
+          <v-toolbar color="white" flat>
+            <v-text-field
+              v-model="search"
+              prepend-inner-icon="mdi-magnify"
+              :placeholder="$gettext('Search')"
+              variant="outlined"
+              single-line
+              flat
+              hide-details
+              density="compact"
+              class="flex-grow-0 w-33 mr-4"
+            ></v-text-field>
+            <v-btn color="primary" variant="outlined" @click="showForm = true">
+              {{ $gettext('Add') }}
+            </v-btn>
+            <template v-if="preferences.enable_carddav_sync">
+              <v-btn class="ml-2" variant="tonal" icon size="small">
+                <v-icon icon="mdi-cog" />
+                <v-menu activator="parent">
+                  <v-list density="compact">
+                    <v-list-item
+                      v-if="!addressBook.last_sync"
+                      color="success"
+                      :title="
+                        $gettext('Synchronize contacts with address book')
+                      "
+                      prepend-icon="mdi-sync"
+                      @click="syncToAddressBook"
+                    />
+                    <v-list-item
+                      :title="$gettext('Synchronize')"
+                      prepend-icon="mdi-sync"
+                      :disabled="addressBook.syncing"
+                      @click="syncFromAddressBook(true)"
+                    />
+                  </v-list>
+                </v-menu>
               </v-btn>
+              <v-btn
+                icon="mdi-information-outline"
+                :title="$gettext('Display address book information')"
+                @click="showAddressBookInfo = true"
+              />
             </template>
-            <MenuItems :items="contactActions" :obj="item" />
-          </v-menu>
-        </div>
-      </template>
-    </v-data-table>
-  </v-card>
-  <v-dialog v-model="showForm" persistent max-width="800px">
-    <ContactForm
-      :contact="selectedContact"
-      @close="closeForm"
-      @added="fetchContacts"
-      @updated="fetchContacts"
-    />
-  </v-dialog>
-  <v-dialog v-model="showCategoriesForm" persistent max-width="800px">
-    <ContactCategoriesForm
-      :contact="selectedContact"
-      @updated="fetchContacts"
-      @close="closeCategoriesForm"
-    />
-  </v-dialog>
-  <v-dialog v-model="showAddressBookInfo" persistent max-width="800px">
-    <AddressBookInfo
-      :address-book-url="addressBook.url"
-      @close="showAddressBookInfo = false"
-    />
-  </v-dialog>
+            <v-chip
+              v-if="$route.params.category"
+              class="my-2 mx-4"
+              label
+              size="small"
+              color="green"
+              prepend-icon="mdi-label"
+              @click="editCategory"
+            >
+              {{ $route.params.category }}
+            </v-chip>
+            <v-spacer></v-spacer>
+            <v-progress-circular
+              v-if="addressBook.syncing"
+              color="primary"
+              indeterminate
+            ></v-progress-circular>
+          </v-toolbar>
+        </template>
+        <template #[`item.display_name`]="{ item }">
+          <template v-if="item.display_name">
+            {{ item.display_name }}
+          </template>
+          <template v-else>
+            {{ item.first_name }} {{ item.last_name }}
+          </template>
+        </template>
+        <template #[`item.emails`]="{ item }">
+          {{ displayEmails(item.emails) }}
+        </template>
+        <template #[`item.phone_numbers`]="{ item }">
+          {{ displayPhoneNumbers(item.phone_numbers) }}
+        </template>
+        <template #[`item.actions`]="{ item }">
+          <div class="text-right">
+            <v-menu offset-y>
+              <template #activator="{ props }">
+                <v-btn icon="mdi-dots-horizontal" variant="text" v-bind="props">
+                </v-btn>
+              </template>
+              <MenuItems :items="contactActions" :obj="item" />
+            </v-menu>
+          </div>
+        </template>
+      </v-data-table>
+    </v-card>
+    <v-dialog v-model="showForm" persistent max-width="800px">
+      <ContactForm
+        :contact="selectedContact"
+        @close="closeForm"
+        @added="fetchContacts"
+        @updated="fetchContacts"
+      />
+    </v-dialog>
+    <v-dialog v-model="showCategoriesForm" persistent max-width="800px">
+      <ContactCategoriesForm
+        :contact="selectedContact"
+        @updated="fetchContacts"
+        @close="closeCategoriesForm"
+      />
+    </v-dialog>
+    <v-dialog v-model="showAddressBookInfo" persistent max-width="800px">
+      <AddressBookInfo
+        :address-book-url="addressBook.url"
+        @close="showAddressBookInfo = false"
+      />
+    </v-dialog>
+  </div>
 </template>
 
 <script setup>
@@ -191,8 +214,18 @@ function deleteContact(contact) {
   })
 }
 
+async function fetchAddressBook() {
+  const resp = await contactsApi.getDefaultAddressBook()
+  addressBook.value = resp.data
+}
+
+async function fetchPreferences() {
+  const resp = await parametersApi.getUserApplication('contacts')
+  preferences.value = resp.data.params
+}
+
 function fetchContacts() {
-  contactsApi.getContacts(route.params).then((resp) => {
+  return contactsApi.getContacts(route.params).then((resp) => {
     contacts.value = resp.data
   })
 }
@@ -203,20 +236,43 @@ function syncToAddressBook() {
   })
 }
 
-contactsApi.getDefaultAddressBook().then((resp) => {
-  addressBook.value = resp.data
-})
-parametersApi.getUserApplication('contacts').then((resp) => {
-  preferences.value = resp.data.params
-})
-fetchContacts()
+async function monitorAddressBook() {
+  await fetchAddressBook()
+  await fetchContacts()
+  if (!addressBook.value.syncing) {
+    clearInterval(intervalId)
+    intervalId = null
+    startAutomaticSync()
+  }
+}
+
+async function syncFromAddressBook(withNotification) {
+  if (intervalId) {
+    // Stop automatic sync for now.
+    clearInterval(intervalId)
+  }
+  await contactsApi.synchronizeFromAddressBook()
+  if (withNotification) {
+    displayNotification({ msg: $gettext('Synchronization started') })
+  }
+  addressBook.value.syncing = true
+  intervalId = setInterval(monitorAddressBook, 5000)
+}
+
+function startAutomaticSync() {
+  intervalId = setInterval(
+    syncFromAddressBook,
+    preferences.value.sync_frequency * 1000
+  )
+}
+
+await fetchAddressBook()
+await fetchPreferences()
+await fetchContacts()
 
 watch(preferences, (value) => {
   if (value) {
-    intervalId = setInterval(
-      contactsApi.synchronizeFromAddressBook,
-      value.sync_frequency * 1000
-    )
+    startAutomaticSync()
   }
 })
 
diff --git a/frontend/src/views/contacts/AddressBook.vue b/frontend/src/views/contacts/AddressBook.vue
index c26ed92ab..e5623abd6 100644
--- a/frontend/src/views/contacts/AddressBook.vue
+++ b/frontend/src/views/contacts/AddressBook.vue
@@ -1,16 +1,18 @@
 <template>
-  <div class="text-h5 ml-4">
-    {{ $gettext('Contacts') }}
+  <div>
+    <div class="text-h5 ml-4">
+      {{ $gettext('Contacts') }}
+    </div>
+    <ContactList @edit-category="openCategoryForm" />
+    <v-dialog v-model="showCategoryForm" persistent max-width="800px">
+      <CategoryForm
+        :category="contactsStore.currentCategory"
+        @close="closeForm"
+        @added="fetchCategories"
+        @updated="fetchCategories"
+      />
+    </v-dialog>
   </div>
-  <ContactList @edit-category="openCategoryForm" />
-  <v-dialog v-model="showCategoryForm" persistent max-width="800px">
-    <CategoryForm
-      :category="contactsStore.currentCategory"
-      @close="closeForm"
-      @added="fetchCategories"
-      @updated="fetchCategories"
-    />
-  </v-dialog>
 </template>
 
 <script setup>
diff --git a/modoboa/contacts/migrations/0008_addressbook_syncing.py b/modoboa/contacts/migrations/0008_addressbook_syncing.py
new file mode 100644
index 000000000..db39c8c2f
--- /dev/null
+++ b/modoboa/contacts/migrations/0008_addressbook_syncing.py
@@ -0,0 +1,18 @@
+# Generated by Django 5.2.9 on 2025-12-12 14:42
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("contacts", "0007_alter_contact_address"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="addressbook",
+            name="syncing",
+            field=models.BooleanField(default=False),
+        ),
+    ]
diff --git a/modoboa/contacts/models.py b/modoboa/contacts/models.py
index 375859835..36dce1ce2 100644
--- a/modoboa/contacts/models.py
+++ b/modoboa/contacts/models.py
@@ -22,6 +22,7 @@ class AddressBook(models.Model):
     name = models.CharField(max_length=50)
     sync_token = models.TextField(blank=True)
     last_sync = models.DateTimeField(null=True)
+    syncing = models.BooleanField(default=False)
     user = models.ForeignKey("core.User", on_delete=models.CASCADE)
     _path = models.TextField()
 
diff --git a/modoboa/contacts/serializers.py b/modoboa/contacts/serializers.py
index 27ee2a753..216934c5e 100644
--- a/modoboa/contacts/serializers.py
+++ b/modoboa/contacts/serializers.py
@@ -14,7 +14,7 @@ class AddressBookSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = models.AddressBook
-        fields = ("pk", "name", "url", "last_sync")
+        fields = ("pk", "name", "url", "last_sync", "syncing")
 
 
 class EmailAddressSerializer(serializers.ModelSerializer):
diff --git a/modoboa/contacts/tasks.py b/modoboa/contacts/tasks.py
index 0726e99ca..f11706b82 100644
--- a/modoboa/contacts/tasks.py
+++ b/modoboa/contacts/tasks.py
@@ -49,12 +49,17 @@ def push_addressbook_to_carddav(request, addressbook):
     addressbook.save(update_fields=["last_sync", "sync_token"])
 
 
-def sync_addressbook_from_cdav(request, addressbook):
+def sync_addressbook_from_cdav(addressbook_id: int, access_token: str):
     """Fetch changes from CardDAV server."""
-    clt = get_cdav_client_from_request(request, addressbook)
+    addressbook = models.AddressBook.objects.get(id=addressbook_id)
+    if addressbook.syncing:
+        return
+    clt = get_cdav_client(addressbook, addressbook.user.email, access_token)
     changes = clt.sync_vcards(addressbook.sync_token)
     if not len(changes["cards"]):
         return
+    addressbook.syncing = True
+    addressbook.save()
     for card in changes["cards"]:
         # UID sometimes embded .vcf extension, sometimes not...
         long_uid = card["href"].split("/")[-1]
@@ -73,7 +78,8 @@ def sync_addressbook_from_cdav(request, addressbook):
             models.Contact.objects.filter(uid__in=[long_uid, short_uid]).delete()
     addressbook.last_sync = timezone.now()
     addressbook.sync_token = changes["token"]
-    addressbook.save(update_fields=["last_sync", "sync_token"])
+    addressbook.syncing = False
+    addressbook.save(update_fields=["last_sync", "sync_token", "syncing"])
 
 
 def push_contact_to_cdav(request, contact):
diff --git a/modoboa/contacts/viewsets.py b/modoboa/contacts/viewsets.py
index 57053ab4c..a283b2b84 100644
--- a/modoboa/contacts/viewsets.py
+++ b/modoboa/contacts/viewsets.py
@@ -1,6 +1,7 @@
 """Contacts viewsets."""
 
 import django_filters.rest_framework
+import django_rq
 from rest_framework.decorators import action
 from rest_framework import filters, response, viewsets
 from rest_framework.permissions import IsAuthenticated
@@ -40,7 +41,8 @@ class AddressBookViewSet(viewsets.GenericViewSet):
         if not abook.last_sync:
             return response.Response()
         if request.user.parameters.get_value("enable_carddav_sync", app="contacts"):
-            tasks.sync_addressbook_from_cdav(request, abook)
+            queue = django_rq.get_queue("modoboa")
+            queue.enqueue(tasks.sync_addressbook_from_cdav, abook.pk, str(request.auth))
         return response.Response({})