diff --git a/addons/mail/models/mail_message.py b/addons/mail/models/mail_message.py
index 4a96c7e4991..daca9e6e019 100644
--- a/addons/mail/models/mail_message.py
+++ b/addons/mail/models/mail_message.py
@@ -974,6 +974,7 @@ class Message(models.Model):
                 'is_discussion': message_sudo.subtype_id.id == com_id,
                 'subtype_description': message_sudo.subtype_id.description,
                 'is_notification': vals['message_type'] == 'user_notification',
+                'recipients': [{'id': p.id, 'name': p.name} for p in message_sudo.partner_ids],
             })
             if vals['model'] and self.env[vals['model']]._original_module:
                 vals['module_icon'] = modules.module.get_module_icon(self.env[vals['model']]._original_module)
@@ -984,7 +985,6 @@ class Message(models.Model):
             'id', 'body', 'date', 'author_id', 'email_from',  # base message fields
             'message_type', 'subtype_id', 'subject',  # message specific
             'model', 'res_id', 'record_name',  # document related
-            'partner_ids',  # recipients
             'starred_partner_ids',  # list of partner ids for whom the message is starred
         ]
 
diff --git a/addons/mail/static/src/models/message/message.js b/addons/mail/static/src/models/message/message.js
index 2769edeebd6..be9d010037a 100644
--- a/addons/mail/static/src/models/message/message.js
+++ b/addons/mail/static/src/models/message/message.js
@@ -106,8 +106,8 @@ registerModel({
                     data2.parentMessage = insertAndReplace(this.convertData(data.parentMessage));
                 }
             }
-            if ('partner_ids' in data && this.messaging.currentPartner) {
-                data2.isCurrentPartnerMentioned = data.partner_ids.includes(this.messaging.currentPartner.id);
+            if ('recipients' in data) {
+                data2.recipients = insertAndReplace(data.recipients);
             }
             if ('starred_partner_ids' in data && this.messaging.currentPartner) {
                 data2.isStarred = data.starred_partner_ids.includes(this.messaging.currentPartner.id);
@@ -421,6 +421,13 @@ registerModel({
             const inlineBody = htmlToTextContentInline(this.body);
             return inlineBody.toLowerCase() === this.subtype_description.toLowerCase();
         },
+        /**
+         * @private
+         * @returns {boolean}
+         */
+        _computeIsCurrentPartnerMentioned() {
+            return this.recipients.includes(this.messaging.currentPartner);
+        },
         /**
          * The method does not attempt to cover all possible cases of empty
          * messages, but mostly those that happen with a standard flow. Indeed
@@ -704,6 +711,7 @@ registerModel({
          * Determine whether the current partner is mentioned.
          */
         isCurrentPartnerMentioned: attr({
+            compute: '_computeIsCurrentPartnerMentioned',
             default: false,
         }),
         /**
@@ -762,6 +770,7 @@ registerModel({
             compute: '_computePrettyBody',
             default: "",
         }),
+        recipients: many('Partner'),
         subject: attr(),
         subtype_description: attr(),
         subtype_id: attr(),
diff --git a/addons/mail/static/src/models/message_view/message_view.js b/addons/mail/static/src/models/message_view/message_view.js
index e0017954358..cc56bfd5c75 100644
--- a/addons/mail/static/src/models/message_view/message_view.js
+++ b/addons/mail/static/src/models/message_view/message_view.js
@@ -75,6 +75,7 @@ registerModel({
             this.update({
                 composerForEditing: insertAndReplace({
                     isLastStateChangeProgrammatic: true,
+                    mentionedPartners: replace(this.message.recipients),
                     textInputContent,
                     textInputCursorEnd: textInputContent.length,
                     textInputCursorStart: textInputContent.length,
diff --git a/addons/mail/static/tests/helpers/mock_server.js b/addons/mail/static/tests/helpers/mock_server.js
index 32cd25dcbc0..a09c02c17e1 100644
--- a/addons/mail/static/tests/helpers/mock_server.js
+++ b/addons/mail/static/tests/helpers/mock_server.js
@@ -1431,12 +1431,17 @@ MockServer.include({
             const trackingValueIds = this._getRecords('mail.tracking.value', [
                 ['id', 'in', message.tracking_value_ids],
             ]);
+            const partners = this._getRecords(
+                'res.partner',
+                [['id', 'in', message.partner_ids]],
+            );
             const response = Object.assign({}, message, {
                 attachment_ids: formattedAttachments,
                 author_id: formattedAuthor,
                 history_partner_ids: historyPartnerIds,
                 needaction_partner_ids: needactionPartnerIds,
                 notifications,
+                recipients: partners.map(p => ({ id: p.id, name: p.name })),
                 record_name: thread && (thread.name !== undefined ? thread.name : thread.display_name),
                 tracking_value_ids: trackingValueIds,
             });
diff --git a/addons/test_mail/tests/test_performance.py b/addons/test_mail/tests/test_performance.py
index b9ec8595e9f..29a014a18a2 100644
--- a/addons/test_mail/tests/test_performance.py
+++ b/addons/test_mail/tests/test_performance.py
@@ -428,7 +428,7 @@ class TestMailAPIPerformance(BaseMailPerformance):
     def test_message_post_one_inbox_notification(self):
         record = self.env['mail.test.simple'].create({'name': 'Test'})
 
-        with self.assertQueryCount(__system__=12, employee=16):
+        with self.assertQueryCount(__system__=13, employee=17):
             record.message_post(
                 body='<p>Test Post Performances with an inbox ping</p>',
                 partner_ids=self.user_test.partner_id.ids,