diff --git a/src/components/MessageList.vue b/src/components/MessageList.vue
index faf6a4c..377d510 100644
--- a/src/components/MessageList.vue
+++ b/src/components/MessageList.vue
@@ -16,12 +16,14 @@ interface Props {
   selectionMode?: boolean
   selectedCollection?: CollectionObject | null
   loading?: boolean
+  searchActive?: boolean
 }
 
 const props = withDefaults(defineProps<Props>(), {
   loading: false,
   selectionList: () => [],
   selectionMode: false,
+  searchActive: false,
 })
 
 // Emits
@@ -372,10 +374,10 @@ onBeforeUnmount(() => {
 
     <!-- Empty state -->
     <div v-else-if="messages.length === 0" class="pa-8 text-center">
-      <v-icon size="64" color="grey-lighten-1">mdi-email-outline</v-icon>
+      <v-icon size="64" color="grey-lighten-1">{{ searchActive ? 'mdi-email-search-outline' : 'mdi-email-outline' }}</v-icon>
       <div class="text-h6 mt-4 text-medium-emphasis">No messages</div>
       <div class="text-body-2 text-medium-emphasis">
-        This folder is empty
+        {{ searchActive ? 'No messages match your search' : 'This folder is empty' }}
       </div>
     </div>
 
diff --git a/src/pages/Main.vue b/src/pages/Main.vue
index b7cbb8f..821381b 100644
--- a/src/pages/Main.vue
+++ b/src/pages/Main.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, onMounted, ref, unref } from 'vue'
+import { computed, onMounted, ref, unref, watch } from 'vue'
 import { storeToRefs } from 'pinia'
 import { useDisplay } from 'vuetify'
 import { useModuleStore } from '@KTXC'
@@ -41,6 +41,8 @@ const {
   loading,
   selectedMessage,
   currentMessages,
+  searchResults,
+  searching,
 } = storeToRefs(mailOperationsStore)
 
 const {
@@ -74,21 +76,19 @@ const {
 // Complex store/composable objects accessed directly (not simple refs)
 const { mailSync, entitiesStore } = mailOperationsStore
 
-// Message search (filters the current message list by subject/sender)
+// Message search — debounced server-side search of the selected folder
 const searchQuery = ref('')
 
-const filteredMessages = computed(() => {
-  const query = (searchQuery.value ?? '').trim().toLowerCase()
-  if (!query) return currentMessages.value
+watch(searchQuery, query => mailOperationsStore.searchMessages(query))
 
-  return currentMessages.value.filter((message: EntityObject) => {
-    const subject = (message.properties.subject || '').toLowerCase()
-    const fromLabel = (message.properties.from?.label || '').toLowerCase()
-    const fromAddress = (message.properties.from?.address || '').toLowerCase()
-    return subject.includes(query) || fromLabel.includes(query) || fromAddress.includes(query)
-  })
+// Reset the search box when the folder changes so it doesn't show a stale
+// query for a folder whose results are no longer being filtered.
+watch(selectedFolder, () => {
+  searchQuery.value = ''
 })
 
+const filteredMessages = computed(() => searchResults.value ?? currentMessages.value)
+
 const lastSyncLabel = computed(() => {
   const lastSync = unref(unref(mailSync.lastSync))
 
@@ -252,6 +252,7 @@ const handleMessageSelectionDelete = () => mailUiStore.deleteSelectedMessages()
         variant="outlined"
         placeholder="Search messages..."
         prepend-inner-icon="mdi-magnify"
+        :loading="searching"
         hide-details
         single-line
         clearable
@@ -310,6 +311,7 @@ const handleMessageSelectionDelete = () => mailUiStore.deleteSelectedMessages()
               :selection-list="selectionList"
               :selection-mode="selectionMode"
               :loading="loading"
+              :search-active="searchResults !== null"
               @open="handleMessageOpen"
               @reply="handleMessageComposeReply"
               @forward="handleMessageComposeForward"
diff --git a/src/stores/mailOperationsStore.ts b/src/stores/mailOperationsStore.ts
index ff9ba1e..64da36b 100644
--- a/src/stores/mailOperationsStore.ts
+++ b/src/stores/mailOperationsStore.ts
@@ -4,7 +4,8 @@ import { useCollectionsStore } from '@MailManager/stores/collectionsStore'
 import { useEntitiesStore } from '@MailManager/stores/entitiesStore'
 import { useServicesStore } from '@MailManager/stores/servicesStore'
 import { useMailSync } from '@MailManager/composables/useMailSync'
-import type { ServiceIdentifier, CollectionIdentifier, EntityIdentifier } from '@MailManager/types/common'
+import type { ServiceIdentifier, CollectionIdentifier, EntityIdentifier, ListFilter } from '@MailManager/types/common'
+import { ListFilterComparisonOperator, ListFilterConjunctionOperator } from '@MailManager/types/common'
 import type { EntityTransmitRequest, EntityBlobSelector } from '@MailManager/types/entity'
 import type { MessageAddressInterface, MessageInterface, MessagePartInterface } from '@MailManager/types/message'
 import { ServiceObject, type CollectionObject, type EntityObject } from '@MailManager/models'
@@ -50,6 +51,8 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
 
   const selectedFolder = shallowRef<CollectionObject | null>(null)
   const selectedMessage = shallowRef<EntityObject | null>(null)
+  const searchResults = shallowRef<EntityObject[] | null>(null)
+  const searching = ref(false)
   const composerSaving = ref(false)
   const composerSending = ref(false)
   const composerLastSaved = ref<Date | null>(null)
@@ -293,6 +296,7 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
   }
 
   async function selectFolder(folder: CollectionObject | null) {
+    clearSearch()
     selectedFolder.value = folder
     selectedMessage.value = null
 
@@ -307,6 +311,67 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
     _updateSyncSources()
   }
 
+  const SEARCH_DEBOUNCE_MS = 300
+  let searchDebounceTimer: ReturnType<typeof setTimeout> | null = null
+  // Monotonic token so out-of-order/stale search responses are discarded.
+  let searchToken = 0
+
+  /**
+   * Debounced server-side search of the selected folder. Clearing the query
+   * (or the folder) reverts the message list back to `currentMessages`.
+   */
+  function searchMessages(query: string) {
+    const trimmed = (query ?? '').trim()
+
+    if (searchDebounceTimer) {
+      clearTimeout(searchDebounceTimer)
+      searchDebounceTimer = null
+    }
+
+    if (!trimmed || !selectedFolder.value) {
+      searchToken++
+      searchResults.value = null
+      searching.value = false
+      return
+    }
+
+    const folder = selectedFolder.value
+    // 'from'/'to'/'subject'/'body' are the attributes both IMAP and JMAP
+    // backends whitelist for entity search (see their entityListFilter
+    // capability); OR them together for a single-box search.
+    const filter: ListFilter = {
+      from: [trimmed, ListFilterComparisonOperator.LIKE],
+      to: [trimmed, ListFilterComparisonOperator.LIKE, ListFilterConjunctionOperator.OR],
+      subject: [trimmed, ListFilterComparisonOperator.LIKE, ListFilterConjunctionOperator.OR],
+      body: [trimmed, ListFilterComparisonOperator.LIKE, ListFilterConjunctionOperator.OR],
+    }
+    searching.value = true
+    const token = ++searchToken
+
+    searchDebounceTimer = setTimeout(async () => {
+      try {
+        const results = await entitiesStore.list([folder.identifier], filter)
+        if (token !== searchToken) return
+        searchResults.value = Object.values(results)
+      } catch (error) {
+        if (token === searchToken) searchResults.value = []
+        console.error('[Mail][Operations] Failed to search messages:', error)
+      } finally {
+        if (token === searchToken) searching.value = false
+      }
+    }, SEARCH_DEBOUNCE_MS)
+  }
+
+  function clearSearch() {
+    if (searchDebounceTimer) {
+      clearTimeout(searchDebounceTimer)
+      searchDebounceTimer = null
+    }
+    searchToken++
+    searchResults.value = null
+    searching.value = false
+  }
+
   function selectMessage(entity: EntityObject | null) {
     selectedMessage.value = entity
   }
@@ -587,6 +652,8 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
     // State
     loading,
     selectedMessage,
+    searchResults,
+    searching,
     composerSaving,
     composerSending,
     composerLastSaved,
@@ -602,6 +669,8 @@ export const useMailOperationsStore = defineStore('mailOperationsStore', () => {
     retrieveService,
     selectFolder,
     selectMessage,
+    searchMessages,
+    clearSearch,
     createFolder,
     saveComposerDraft,
     sendComposerMessage,