diff --git a/addons/mail/static/src/components/chatter/chatter_tests.js b/addons/mail/static/src/components/chatter/chatter_tests.js
index 15163e85709..c5800f685a1 100644
--- a/addons/mail/static/src/components/chatter/chatter_tests.js
+++ b/addons/mail/static/src/components/chatter/chatter_tests.js
@@ -334,6 +334,69 @@ QUnit.test('composer show/hide on log note/send message [REQUIRE FOCUS]', async
     );
 });
 
+QUnit.test('should display subject when subject is not the same as the thread name', async function (assert) {
+    assert.expect(2);
+
+    this.data['res.partner'].records.push({ id: 100 });
+    this.data['mail.message'].records.push({
+        body: "not empty",
+        model: 'res.partner',
+        res_id: 100,
+        subject: "Salutations, voyageur",
+    });
+    await this.start();
+    const thread = this.env.models['mail.thread'].create({
+        id: 100,
+        model: 'res.partner',
+        name: "voyageur",
+    });
+    const chatter = this.env.models['mail.chatter'].create({
+        threadId: 100,
+        threadModel: 'res.partner',
+    });
+    await this.createChatterComponent({ chatter });
+
+    assert.containsOnce(
+        document.body,
+        '.o_Message_subject',
+        "should display subject of the message"
+    );
+    assert.strictEqual(
+        document.querySelector('.o_Message_subject').textContent,
+        "Subject: Salutations, voyageur",
+        "Subject of the message should be 'Salutations, voyageur'"
+    );
+});
+
+QUnit.test('should not display subject when subject is the same as the thread name', async function (assert) {
+    assert.expect(1);
+
+    this.data['res.partner'].records.push({ id: 100 });
+    this.data['mail.message'].records.push({
+        body: "not empty",
+        model: 'res.partner',
+        res_id: 100,
+        subject: "Salutations, voyageur",
+    });
+    await this.start();
+    const thread = this.env.models['mail.thread'].create({
+        id: 100,
+        model: 'res.partner',
+        name: "Salutations, voyageur",
+    });
+    const chatter = this.env.models['mail.chatter'].create({
+        threadId: 100,
+        threadModel: 'res.partner',
+    });
+    await this.createChatterComponent({ chatter });
+
+    assert.containsNone(
+        document.body,
+        '.o_Message_subject',
+        "should not display subject of the message"
+    );
+});
+
 QUnit.test('should not display user notification messages in chatter', async function (assert) {
     assert.expect(1);
 
diff --git a/addons/mail/static/src/components/message/message.js b/addons/mail/static/src/components/message/message.js
index 3f5314eef13..a954b697a69 100644
--- a/addons/mail/static/src/components/message/message.js
+++ b/addons/mail/static/src/components/message/message.js
@@ -79,7 +79,6 @@ class Message extends Component {
                 partnerRoot,
                 thread,
                 threadHasSeenIndicators: thread && thread.hasSeenIndicators,
-                threadMassMailing: thread && thread.mass_mailing,
             };
         }, {
             compareDepth: {
diff --git a/addons/mail/static/src/components/message/message.xml b/addons/mail/static/src/components/message/message.xml
index f67fb41673f..ba16591aee3 100644
--- a/addons/mail/static/src/components/message/message.xml
+++ b/addons/mail/static/src/components/message/message.xml
@@ -180,7 +180,7 @@
                             </ul>
                         </t>
                     </div>
-                    <t t-if="message.subject and !message.isSubjectSimilarToOriginThreadName and threadView and threadView.thread and (threadView.thread.mass_mailing or [env.messaging.inbox, env.messaging.history].includes(threadView.thread))">
+                    <t t-if="message.subject and !message.isSubjectSimilarToOriginThreadName">
                         <p class="o_Message_subject">Subject: <t t-esc="message.subject"/></p>
                     </t>
                     <t t-if="message.attachments and message.attachments.length > 0">
diff --git a/addons/mail/static/src/components/thread_view/thread_view_tests.js b/addons/mail/static/src/components/thread_view/thread_view_tests.js
index 9fadeea475f..8b3e08cbf15 100644
--- a/addons/mail/static/src/components/thread_view/thread_view_tests.js
+++ b/addons/mail/static/src/components/thread_view/thread_view_tests.js
@@ -453,13 +453,12 @@ QUnit.test('mark channel as fetched and seen when a new message is loaded if com
     );
 });
 
-QUnit.test('show message subject if thread is mailing channel', async function (assert) {
+QUnit.test('show message subject when subject is not the same as the thread name', async function (assert) {
     assert.expect(3);
 
     this.data['mail.channel'].records.push({
         channel_type: 'channel',
         id: 100,
-        mass_mailing: true,
         name: "General",
         public: 'public',
     });
@@ -497,6 +496,39 @@ QUnit.test('show message subject if thread is mailing channel', async function (
     );
 });
 
+QUnit.test('do not show message subject when subject is the same as the thread name', async function (assert) {
+    assert.expect(1);
+
+    this.data['mail.channel'].records.push({
+        channel_type: 'channel',
+        id: 100,
+        name: "Salutations, voyageur",
+        public: 'public',
+    });
+    this.data['mail.message'].records.push({
+        body: "not empty",
+        model: 'mail.channel',
+        res_id: 100,
+        subject: "Salutations, voyageur",
+    });
+    await this.start();
+    const thread = this.env.models['mail.thread'].findFromIdentifyingData({
+        id: 100,
+        model: 'mail.channel',
+    });
+    const threadViewer = this.env.models['mail.thread_viewer'].create({
+        hasThreadView: true,
+        thread: [['link', thread]],
+    });
+    await this.createThreadViewComponent(threadViewer.threadView);
+
+    assert.containsNone(
+        document.body,
+        '.o_Message_subject',
+        "should not display subject of the message"
+    );
+});
+
 QUnit.test('[technical] new messages separator on posting message', async function (assert) {
     // technical as we need to remove focus from text input to avoid `channel_seen` call
     assert.expect(4);