diff --git a/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.js b/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.js
index 4396c78b8c8..769217d399a 100644
--- a/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.js
+++ b/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.js
@@ -10,34 +10,6 @@ export class DiscussMobileMailboxSelection extends Component {
     // Public
     //--------------------------------------------------------------------------
 
-    /**
-     * @returns {Thread[]}
-     */
-    get orderedMailboxes() {
-        if (!this.messaging) {
-            return [];
-        }
-        return this.messaging.models['Thread']
-            .all(thread => thread.isPinned && thread.model === 'mail.box')
-            .sort((mailbox1, mailbox2) => {
-                if (mailbox1 === this.messaging.inbox) {
-                    return -1;
-                }
-                if (mailbox2 === this.messaging.inbox) {
-                    return 1;
-                }
-                if (mailbox1 === this.messaging.starred) {
-                    return -1;
-                }
-                if (mailbox2 === this.messaging.starred) {
-                    return 1;
-                }
-                const mailbox1Name = mailbox1.displayName;
-                const mailbox2Name = mailbox2.displayName;
-                mailbox1Name < mailbox2Name ? -1 : 1;
-            });
-    }
-
     /**
      * @returns {Discuss}
      */
diff --git a/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.xml b/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.xml
index 413e5cd0c0a..84611f45924 100644
--- a/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.xml
+++ b/addons/mail/static/src/components/discuss_mobile_mailbox_selection/discuss_mobile_mailbox_selection.xml
@@ -3,7 +3,7 @@
 
     <t t-name="mail.DiscussMobileMailboxSelection" owl="1">
         <div class="o_DiscussMobileMailboxSelection" t-attf-class="{{ className }}" t-ref="root">
-            <t t-foreach="orderedMailboxes" t-as="mailbox" t-key="mailbox.localId">
+            <t t-foreach="discuss.orderedMailboxes" t-as="mailbox" t-key="mailbox.localId">
                 <button class="o_DiscussMobileMailboxSelection_button btn btn-secondary"
                     t-att-class="{
                         'active o-active': discuss.thread === mailbox,
diff --git a/addons/mail/static/src/models/discuss.js b/addons/mail/static/src/models/discuss.js
index fc2075f63db..c44eee4de82 100644
--- a/addons/mail/static/src/models/discuss.js
+++ b/addons/mail/static/src/models/discuss.js
@@ -1,8 +1,8 @@
 /** @odoo-module **/
 
 import { registerModel } from '@mail/model/model_core';
-import { attr, one } from '@mail/model/model_field';
-import { clear, insertAndReplace, link, unlink } from '@mail/model/model_field_command';
+import { attr, many, one } from '@mail/model/model_field';
+import { clear, insertAndReplace, link, replace, unlink } from '@mail/model/model_field_command';
 import { escape } from '@web/core/utils/strings';
 
 registerModel({
@@ -316,6 +316,35 @@ registerModel({
         _computeNotificationListView() {
             return (this.messaging.device.isMobile && this.activeMobileNavbarTabId !== 'mailbox') ? insertAndReplace() : clear();
         },
+        /**
+         * @private
+         * @returns {FieldCommand}
+         */
+        _computeOrderedMailboxes() {
+            if (!this.messaging) {
+                return clear();
+            }
+            const orderedMailboxes = this.messaging.models['Thread']
+                .all(thread => thread.isPinned && thread.model === 'mail.box')
+                .sort((mailbox1, mailbox2) => {
+                    if (mailbox1 === this.messaging.inbox) {
+                        return -1;
+                    }
+                    if (mailbox2 === this.messaging.inbox) {
+                        return 1;
+                    }
+                    if (mailbox1 === this.messaging.starred) {
+                        return -1;
+                    }
+                    if (mailbox2 === this.messaging.starred) {
+                        return 1;
+                    }
+                    const mailbox1Name = mailbox1.displayName;
+                    const mailbox2Name = mailbox2.displayName;
+                    return mailbox1Name < mailbox2Name ? -1 : 1;
+                });
+            return replace(orderedMailboxes);
+        },
         /**
          * Only pinned threads are allowed in discuss.
          *
@@ -443,6 +472,9 @@ registerModel({
             inverse: 'discuss',
             isCausal: true,
         }),
+        orderedMailboxes: many('Thread', {
+            compute: '_computeOrderedMailboxes',
+        }),
         /**
          * Quick search input value in the discuss sidebar (desktop). Useful
          * to filter channels and chats based on this input content.