diff --git a/frontend/src/api/account.js b/frontend/src/api/account.js
index 9caad38ae..1375c2436 100644
--- a/frontend/src/api/account.js
+++ b/frontend/src/api/account.js
@@ -94,6 +94,16 @@ export default {
       `${resource}/filtersets/${filterSetName}/filters/${filter}/disable/`
     )
   },
+  moveFilterDown(filterSetName, filter) {
+    return repository.post(
+      `${resource}/filtersets/${filterSetName}/filters/${filter}/move_down/`
+    )
+  },
+  moveFilterUp(filterSetName, filter) {
+    return repository.post(
+      `${resource}/filtersets/${filterSetName}/filters/${filter}/move_up/`
+    )
+  },
   enableFilter(filterSetName, filter) {
     return repository.post(
       `${resource}/filtersets/${filterSetName}/filters/${filter}/enable/`
diff --git a/frontend/src/components/account/FilterForm.vue b/frontend/src/components/account/FilterForm.vue
index 292ae4d00..6a226e6b8 100644
--- a/frontend/src/components/account/FilterForm.vue
+++ b/frontend/src/components/account/FilterForm.vue
@@ -10,8 +10,9 @@
           variant="outlined"
           density="compact"
           :rules="[rules.required]"
+          :error-messages="apiErrors.name ? apiErrors.name : []"
         />
-        <div>
+        <div class="bg-grey-lighten-4 rounded pa-3">
           <h4>{{ $gettext('Conditions') }}</h4>
           <v-radio-group
             v-model="form.match_type"
@@ -42,7 +43,6 @@
                 variant="outlined"
                 density="compact"
                 :rules="[rules.required]"
-                @update:model-value=""
               />
               <v-select
                 v-model="condition.operator"
@@ -83,7 +83,7 @@
             </div>
           </template>
         </div>
-        <div>
+        <div class="mt-4 bg-grey-lighten-4 rounded pa-3">
           <h4>{{ $gettext('Actions') }}</h4>
           <div v-for="(action, index) in form.actions" class="d-flex align-start mt-2">
             <v-select
@@ -140,11 +140,12 @@
       <v-spacer></v-spacer>
       <v-btn
         :text="$gettext('Cancel')"
-        variant="plain"
+        variant="elevated"
         @click="close"
       ></v-btn>
       <v-btn
         color="primary"
+        variant="elevated"
         :text="submitLabel"
         :loading="working"
         @click="submit"
@@ -175,6 +176,7 @@ const emit = defineEmits(['close'])
 const busStore = useBusStore()
 const { $gettext } = useGettext()
 
+const apiErrors = ref({})
 const conditionTemplates = ref([])
 const actionTemplates = ref([])
 const formRef = ref()
@@ -290,8 +292,8 @@ async function submit() {
       msg = $gettext('Filter updated')
     }
   } catch (err) {
-    if (err.response.data && err.response.data.error) {
-      busStore.displayNotification({ msg: err.response.data.error, type: 'error' })
+    if (err.response.status === 400 && err.response.data) {
+      apiErrors.value = err.response.data
     }
     return
   } finally {
diff --git a/frontend/src/views/account/FiltersView.vue b/frontend/src/views/account/FiltersView.vue
index 8fb2cc555..b4621b002 100644
--- a/frontend/src/views/account/FiltersView.vue
+++ b/frontend/src/views/account/FiltersView.vue
@@ -55,11 +55,11 @@
     >
       <template v-if="!rawMode">
         <div class="d-flex align-center">
-          <v-spacer />
           <v-btn
             color="primary"
             :title="$gettext('Add new filter')"
             @click="showFilterForm = true"
+            class="mx-auto"
           >
             <v-icon icon="mdi-plus" />
             {{ $gettext('Add') }}
@@ -73,7 +73,7 @@
           <template #[`item.enabled`]="{ item }">
             {{ $yesno(item.enabled) }}
           </template>
-          <template #[`item.filter_actions`]="{ item }">
+          <template #[`item.filter_actions`]="{ index, item }">
             <v-menu offset-y>
               <template #activator="{ props }">
                 <v-btn
@@ -83,21 +83,26 @@
                 >
                 </v-btn>
               </template>
-              <MenuItems :items="getFilterActions(item)" :obj="item" />
+              <MenuItems :items="getFilterActions(item, index)" :obj="item" />
             </v-menu>
           </template>
         </v-data-table>
       </template>
       <template v-else>
-        <v-textarea
-          v-model="filterSetRawContent"
-          variant="outlined"
-          auto-grow
-        />
+        <v-form ref="rawFormRef">
+          <v-textarea
+            v-model="filterSetRawContent"
+            variant="outlined"
+            auto-grow
+            :rules="[rules.required]"
+            :error-messages="rawContentErrors"
+          />
+        </v-form>
         <v-btn
           color="success"
           @click="saveFilterSet"
           :loading="saving"
+          class="mt-2"
         >
           {{ $gettext('Save') }}
         </v-btn>
@@ -131,6 +136,7 @@ import { ref, watch } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
 import { useGettext } from 'vue3-gettext'
 import { useBusStore } from '@/stores'
+import rules from '@/plugins/rules'
 import accountApi from '@/api/account'
 import FilterSetForm from '@/components/account/FilterSetForm.vue'
 import FilterForm from '@/components/account/FilterForm.vue'
@@ -146,6 +152,8 @@ const filters = ref([])
 const filterSetRawContent = ref('')
 const currentFilterSet = ref()
 const loadingFilters = ref(false)
+const rawContentErrors = ref([])
+const rawFormRef = ref()
 const rawMode = ref(false)
 const saving = ref(false)
 const selectedFilter = ref(null)
@@ -181,6 +189,12 @@ watch(rawMode, (value) => {
   }
 })
 
+watch(filterSetRawContent, () => {
+  if (rawContentErrors.value.length) {
+    rawContentErrors.value = []
+  }
+})
+
 function getFilterSetName(filterSet) {
   let result = filterSet.name
   if (filterSet.active) {
@@ -248,6 +262,16 @@ function deleteFilter(filter) {
   })
 }
 
+async function moveFilterDown(filter) {
+  await accountApi.moveFilterDown(currentFilterSet.value.name, filter.name)
+  fetchFilters(currentFilterSet.value.name)
+}
+
+async function moveFilterUp(filter) {
+  await accountApi.moveFilterUp(currentFilterSet.value.name, filter.name)
+  fetchFilters(currentFilterSet.value.name)
+}
+
 async function activateFilterSet(filterSet) {
   await accountApi.activateFilterSet(filterSet.name)
   busStore.displayNotification({ msg: $gettext('Filter set activated') })
@@ -261,11 +285,22 @@ async function deleteFilterSet(filterSet) {
 }
 
 async function saveFilterSet() {
+  const { valid } = await rawFormRef.value.validate()
+  if (!valid) {
+    return
+  }
   const data = { content: filterSetRawContent.value }
   saving.value = true
-  await accountApi.saveFilterSet(currentFilterSet.value.name, data)
-  saving.value = false
-  busStore.displayNotification({ msg: $gettext('Filter set updated') })
+  try {
+    await accountApi.saveFilterSet(currentFilterSet.value.name, data)
+    busStore.displayNotification({ msg: $gettext('Filter set updated') })
+  } catch (err) {
+    if (err.response.status === 400 && err.response.data.content) {
+      rawContentErrors.value = err.response.data.content
+    }
+  } finally {
+    saving.value = false
+  }
 }
 
 async function downloadFilterSet(filterSet) {
@@ -292,7 +327,7 @@ const filterActions = [
   }
 ]
 
-function getFilterActions(filter) {
+function getFilterActions(filter, index) {
   const result = [...filterActions]
   if (filter.enabled) {
     result.push({
@@ -309,6 +344,20 @@ function getFilterActions(filter) {
       onClick: enableFilter
     })
   }
+  if (index !== filters.value.length - 1) {
+    result.push({
+      label: $gettext('Move down'),
+      icon: 'mdi-arrow-down',
+      onClick: moveFilterDown
+    })
+  }
+  if (index !== 0) {
+    result.push({
+      label: $gettext('Move up'),
+      icon: 'mdi-arrow-up',
+      onClick: moveFilterUp
+    })
+  }
   return result
 }
 
@@ -341,12 +390,3 @@ function getFilterSetActions() {
 
 fetchFilterSets()
 </script>
-
-<style scoped>
- /* .v-toolbar {
-    background-color: white !important;
-    } */
- .v-tabs {
-   background-color: #f7f8fa !important;
- }
-</style>
diff --git a/modoboa/sievefilters/api/v2/serializers.py b/modoboa/sievefilters/api/v2/serializers.py
index dd9eec624..f492959d1 100644
--- a/modoboa/sievefilters/api/v2/serializers.py
+++ b/modoboa/sievefilters/api/v2/serializers.py
@@ -5,6 +5,8 @@ from typing import List, Tuple
 from sievelib import commands
 from sievelib.factory import Filter
 
+from django.utils.translation import gettext as _
+
 from rest_framework import serializers
 
 from modoboa.sievefilters import constants, lib
@@ -20,6 +22,13 @@ class FilterSetContentSerializer(serializers.Serializer):
 
     content = serializers.CharField()
 
+    def validate_content(self, value: str):
+        sclient = self.context["sclient"]
+        if not sclient.msc.checkscript(value):
+            error = sclient.msc.errmsg.decode().strip().split("\r\n")[0]
+            raise serializers.ValidationError(error)
+        return value
+
 
 class ConditionSerializer(serializers.Serializer):
 
diff --git a/modoboa/sievefilters/api/v2/viewsets.py b/modoboa/sievefilters/api/v2/viewsets.py
index 6dbba9853..e3cdc60ae 100644
--- a/modoboa/sievefilters/api/v2/viewsets.py
+++ b/modoboa/sievefilters/api/v2/viewsets.py
@@ -7,6 +7,7 @@ from sievelib.commands import BadArgument, BadValue
 from sievelib.factory import FilterAlreadyExists
 
 from django.http import HttpResponse
+from django.utils.translation import gettext as _
 
 from drf_spectacular.types import OpenApiTypes
 from drf_spectacular.utils import extend_schema, OpenApiParameter
@@ -20,6 +21,14 @@ from modoboa.sievefilters.rfc6266 import build_header
 from modoboa.sievefilters.api.v2 import serializers
 
 
+FILTER_SET_ID = OpenApiParameter(
+    "id",
+    OpenApiTypes.STR,
+    description="Name of an existing filter set",
+    location=OpenApiParameter.PATH,
+)
+
+
 class FilterSetViewSet(viewsets.ViewSet):
 
     serializer_class = serializers.FilterSetSerializer
@@ -62,12 +71,15 @@ class FilterSetViewSet(viewsets.ViewSet):
             fset = sclient.getscript(pk)
         except SieveClientError:
             return response.Response(status=404)
-        serializer = serializers.FilterSetContentSerializer(data=request.data)
+        serializer = serializers.FilterSetContentSerializer(
+            data=request.data, context={"sclient": sclient}
+        )
         serializer.is_valid(raise_exception=True)
         try:
             sclient.pushscript(pk, serializer.validated_data["content"])
         except SieveClientError as e:
             error = str(e)
+            return response.Response({"content": error}, status=400)
         return response.Response(serializer.validated_data)
 
     @action(methods=["post"], detail=True)
@@ -135,22 +147,33 @@ class FilterSetViewSet(viewsets.ViewSet):
         return response.Response(serializer.data)
 
     @extend_schema(
-        parameters=[
-            OpenApiParameter("id", OpenApiTypes.STR),
-        ],
-        request=serializers.FilterSerializer,
-        responses={201: serializers.FilterSerializer},
+        parameters=[FILTER_SET_ID],
+        responses={200: serializers.FilterSerializer(many=True)},
     )
-    @action(methods=["get", "post"], detail=True)
-    def filters(self, request, pk=None):
+    @action(methods=["get"], detail=True, url_path="filters")
+    def get_filters(self, request, pk=None):
+        """Retrieve a list of all filters associated to given filter set."""
+        sclient = self.get_sieve_client(request)
+        try:
+            fset = sclient.getscript(pk, format="fset")
+        except SieveClientError:
+            return response.Response(status=404)
+        serializer = serializers.FilterSerializer.from_filters(fset.filters)
+        return response.Response(serializer.data)
+
+    @extend_schema(
+        parameters=[FILTER_SET_ID],
+        request=serializers.FilterSerializer,
+        responses={201: serializers.FilterSerializer},
+    )
+    @get_filters.mapping.post
+    def filters(self, request, pk=None):
+        """Create a new filter."""
         sclient = self.get_sieve_client(request)
         try:
             fset = sclient.getscript(pk, format="fset")
         except SieveClientError:
             return response.Response(status=404)
-        if request.method == "GET":
-            serializer = serializers.FilterSerializer.from_filters(fset.filters)
-            return response.Response(serializer.data)
         serializer = serializers.FilterSerializer(data=request.data)
         serializer.is_valid(raise_exception=True)
         match_type, conditions, actions = serializer.to_filter()
@@ -160,8 +183,8 @@ class FilterSetViewSet(viewsets.ViewSet):
         except (BadArgument, BadValue) as inst:
             return response.Response(str(inst), status=400)
         except FilterAlreadyExists:
-            return response.Response(
-                {"error": f"Filter {fset.name} already exists"}, status=409
+            raise serializers.ValidationError(
+                {"name": _("Filter %s already exists") % fltname}
             )
         sclient.pushscript(fset.name, str(fset))
         return response.Response(serializer.validated_data, status=201)
@@ -169,7 +192,7 @@ class FilterSetViewSet(viewsets.ViewSet):
     @extend_schema(
         description="Update an existing filter",
         parameters=[
-            OpenApiParameter("id", OpenApiTypes.STR, location=OpenApiParameter.PATH),
+            FILTER_SET_ID,
             OpenApiParameter(
                 "filter", OpenApiTypes.STR, location=OpenApiParameter.PATH
             ),
@@ -226,7 +249,7 @@ class FilterSetViewSet(viewsets.ViewSet):
     @extend_schema(
         description="Delete an existing filter",
         parameters=[
-            OpenApiParameter("id", OpenApiTypes.STR, location=OpenApiParameter.PATH),
+            FILTER_SET_ID,
             OpenApiParameter(
                 "filter", OpenApiTypes.STR, location=OpenApiParameter.PATH
             ),
@@ -243,3 +266,25 @@ class FilterSetViewSet(viewsets.ViewSet):
             sclient.pushscript(fset.name, str(fset))
             return response.Response(status=204)
         return response.Response(status=404)
+
+    def move_filter(self, request, filterset: str, filter: str, direction: str):
+        sclient = self.get_sieve_client(request)
+        try:
+            fset = sclient.getscript(filterset, format="fset")
+        except SieveClientError:
+            return response.Response(status=404)
+        fset.movefilter(filter, direction)
+        sclient.pushscript(filterset, str(fset))
+        return response.Response(status=204)
+
+    @action(
+        methods=["post"], detail=True, url_path="filters/(?P<filter>[^/.]+)/move_up"
+    )
+    def move_filter_up(self, request, pk: str, filter: str):
+        return self.move_filter(request, pk, filter, "up")
+
+    @action(
+        methods=["post"], detail=True, url_path="filters/(?P<filter>[^/.]+)/move_down"
+    )
+    def move_filter_down(self, request, pk: str, filter: str):
+        return self.move_filter(request, pk, filter, "down")