diff --git a/addons/mail/static/src/components/attachment/attachment.js b/addons/mail/static/src/components/attachment/attachment.js
index a17ed341b9a..9d64324d9b7 100644
--- a/addons/mail/static/src/components/attachment/attachment.js
+++ b/addons/mail/static/src/components/attachment/attachment.js
@@ -3,7 +3,11 @@ odoo.define('mail/static/src/components/attachment/attachment.js', function (req
 
 const useStore = require('mail/static/src/component_hooks/use_store/use_store.js');
 
-const { Component } = owl;
+const components = {
+    AttachmentDeleteConfirmDialog: require('mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js'),
+};
+
+const { Component, useState } = owl;
 
 class Attachment extends Component {
 
@@ -18,6 +22,9 @@ class Attachment extends Component {
                 attachment: attachment ? attachment.__state : undefined,
             };
         });
+        this.state = useState({
+            hasDeleteConfirmDialog: false,
+        });
     }
 
     //--------------------------------------------------------------------------
@@ -125,13 +132,24 @@ class Attachment extends Component {
      */
     _onClickUnlink(ev) {
         ev.stopPropagation();
-        this.attachment.remove();
-        this.trigger('o-attachment-removed');
+        if (this.attachment.isLinkedToComposer) {
+            this.attachment.remove();
+            this.trigger('o-attachment-removed', { attachmentLocalId: this.props.attachmentLocalId });
+        } else {
+            this.state.hasDeleteConfirmDialog = true;
+        }
     }
 
+   /**
+    * @private
+    */
+    _onDeleteConfirmDialogClosed() {
+        this.state.hasDeleteConfirmDialog = false;
+    }
 }
 
 Object.assign(Attachment, {
+    components,
     defaultProps: {
         attachmentLocalIds: [],
         detailsMode: 'auto',
diff --git a/addons/mail/static/src/components/attachment/attachment.xml b/addons/mail/static/src/components/attachment/attachment.xml
index 7be59392838..96e96b407ee 100644
--- a/addons/mail/static/src/components/attachment/attachment.xml
+++ b/addons/mail/static/src/components/attachment/attachment.xml
@@ -102,6 +102,12 @@
                         </t>
                     </div>
                 </t>
+                <t t-if="state.hasDeleteConfirmDialog">
+                    <AttachmentDeleteConfirmDialog
+                        attachmentLocalId="props.attachmentLocalId"
+                        t-on-dialog-closed="_onDeleteConfirmDialogClosed"
+                    />
+                </t>
             </t>
         </div>
     </t>
diff --git a/addons/mail/static/src/components/attachment_box/attachment_box_tests.js b/addons/mail/static/src/components/attachment_box/attachment_box_tests.js
index 9330a8c955b..6f217c2b5d7 100644
--- a/addons/mail/static/src/components/attachment_box/attachment_box_tests.js
+++ b/addons/mail/static/src/components/attachment_box/attachment_box_tests.js
@@ -284,6 +284,54 @@ QUnit.test('view attachments', async function (assert) {
     );
 });
 
+QUnit.test('remove attachment should ask for confirmation', async function (assert) {
+    assert.expect(5);
+
+    await this.start();
+    const thread = this.env.models['mail.thread'].create({
+        attachments: [
+            ['insert', {
+                id: 143,
+                mimetype: 'text/plain',
+                name: 'Blah.txt'
+            }],
+        ],
+        id: 100,
+        model: 'res.partner',
+    });
+    await this.createAttachmentBoxComponent(thread);
+    assert.containsOnce(
+        document.body,
+        '.o_Attachment',
+        "should have an attachment",
+    );
+    assert.containsOnce(
+        document.body,
+        '.o_Attachment_actionUnlink',
+        "attachment should have a delete button"
+    );
+
+    await afterNextRender(() => document.querySelector('.o_Attachment_actionUnlink').click());
+    assert.containsOnce(
+        document.body,
+        '.o_AttachmentDeleteConfirmDialog',
+        "A confirmation dialog should have been opened"
+    );
+    assert.strictEqual(
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_mainText').textContent,
+        `Do you really want to delete "Blah.txt"?`,
+        "Confirmation dialog should contain the attachment delete confirmation text"
+    );
+
+    // Confirm the deletion
+    await afterNextRender(() => document.querySelector('.o_AttachmentDeleteConfirmDialog_confirmButton').click());
+    assert.containsNone(
+        document.body,
+        '.o_Attachment',
+        "should no longer have an attachment",
+    );
+});
+
 });
 });
 });
diff --git a/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js b/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js
index 3b4527b3677..46fa1c65260 100644
--- a/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js
+++ b/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js
@@ -1,6 +1,90 @@
 odoo.define('mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.js', function (require) {
 'use strict';
 
-// TODO FIXME file to be completed in task-2282322
+const useStore = require('mail/static/src/component_hooks/use_store/use_store.js');
+
+const components = {
+    Dialog: require('web.OwlDialog'),
+};
+
+const { Component } = owl;
+const { useRef } = owl.hooks;
+
+class AttachmentDeleteConfirmDialog extends Component {
+
+    /**
+     * @override
+     */
+    constructor(...args) {
+        super(...args);
+        useStore(props => {
+            const attachment = this.env.models['mail.attachment'].get(props.attachmentLocalId);
+            return {
+                attachment: attachment ? attachment.__state : undefined,
+            };
+        });
+        // to manually trigger the dialog close event
+        this._dialogRef = useRef('dialog');
+    }
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+    /**
+     * @returns {mail.attachment}
+     */
+    get attachment() {
+        return this.env.models['mail.attachment'].get(this.props.attachmentLocalId);
+    }
+
+    /**
+     * @returns {string}
+     */
+    getBody() {
+        return _.str.sprintf(
+            this.env._t(`Do you really want to delete "%s"?`),
+            owl.utils.escape(this.attachment.displayName)
+        );
+    }
+
+    /**
+     * @returns {string}
+     */
+    getTitle() {
+        return this.env._t("Confirmation");
+    }
+
+    //--------------------------------------------------------------------------
+    // Handlers
+    //--------------------------------------------------------------------------
+
+    /**
+     * @private
+     */
+    _onClickCancel() {
+        this._dialogRef.comp._close();
+    }
+
+    /**
+     * @private
+     */
+    _onClickOk() {
+        this._dialogRef.comp._close();
+        this.attachment.remove();
+        this.trigger('o-attachment-removed', { attachmentLocalId: this.props.attachmentLocalId });
+    }
+
+}
+
+Object.assign(AttachmentDeleteConfirmDialog, {
+    components,
+    props: {
+        attachmentLocalId: String,
+    },
+    template: 'mail.AttachmentDeleteConfirmDialog',
+});
+
+return AttachmentDeleteConfirmDialog;
 
 });
diff --git a/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.xml b/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.xml
index c98c47daf1b..6b466a9ba2d 100644
--- a/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.xml
+++ b/addons/mail/static/src/components/attachment_delete_confirm_dialog/attachment_delete_confirm_dialog.xml
@@ -1,4 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <templates xml:space="preserve">
-    <!-- TODO FIXME file to be completed in task-2282322 -->
+    <t t-name="mail.AttachmentDeleteConfirmDialog" owl="1">
+        <Dialog contentClass="'o_AttachmentDeleteConfirmDialog'" title="getTitle()" size="'medium'" t-ref="dialog">
+            <p class="o_AttachmentDeleteConfirmDialog_mainText" t-esc="getBody()"/>
+            <t t-set-slot="buttons">
+                <button class="o_AttachmentDeleteConfirmDialog_confirmButton btn btn-primary" t-on-click="_onClickOk">Ok</button>
+                <button class="o_AttachmentDeleteConfirmDialog_cancelButton btn btn-secondary" t-on-click="_onClickCancel">Cancel</button>
+            </t>
+        </Dialog>
+    </t>
 </templates>
diff --git a/addons/mail/static/src/components/chat_window_manager/chat_window_manager_tests.js b/addons/mail/static/src/components/chat_window_manager/chat_window_manager_tests.js
index 1a261265dc7..bf9db6c0276 100644
--- a/addons/mail/static/src/components/chat_window_manager/chat_window_manager_tests.js
+++ b/addons/mail/static/src/components/chat_window_manager/chat_window_manager_tests.js
@@ -802,9 +802,8 @@ QUnit.test('[technical] chat window: scroll conservation on toggle home menu', a
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i < 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
-            model: 'mail.channel',
-            res_id: 20,
         });
     }
     await this.start();
@@ -1543,9 +1542,8 @@ QUnit.test('chat window with a thread: keep scroll position in message list on f
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i < 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
-            model: 'mail.channel',
-            res_id: 20,
         });
     }
     await this.start();
@@ -1588,9 +1586,8 @@ QUnit.test('chat window should scroll to the newly posted message just after pos
     });
     for (let i = 0; i < 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
-            model: 'mail.channel',
-            res_id: 20,
         });
     }
     await this.start();
@@ -1710,9 +1707,8 @@ QUnit.test('[technical] chat window with a thread: keep scroll position in messa
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i < 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
-            model: 'mail.channel',
-            res_id: 20,
         });
     }
     await this.start();
diff --git a/addons/mail/static/src/components/chatter/chatter_tests.js b/addons/mail/static/src/components/chatter/chatter_tests.js
index 95abab26f43..9057f0684ab 100644
--- a/addons/mail/static/src/components/chatter/chatter_tests.js
+++ b/addons/mail/static/src/components/chatter/chatter_tests.js
@@ -47,6 +47,7 @@ QUnit.test('base rendering when chatter has no attachment', async function (asse
     this.data['res.partner'].records.push({ id: 100 });
     for (let i = 0; i < 60; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             model: 'res.partner',
             res_id: 100,
         });
diff --git a/addons/mail/static/src/components/composer/composer_tests.js b/addons/mail/static/src/components/composer/composer_tests.js
index d37162ffa8d..4910dfb7c43 100644
--- a/addons/mail/static/src/components/composer/composer_tests.js
+++ b/addons/mail/static/src/components/composer/composer_tests.js
@@ -1746,6 +1746,44 @@ QUnit.test('warning on send with shortcut when attempting to post message with s
     );
 });
 
+QUnit.test('remove an attachment from composer does not need any confirmation', async function (assert) {
+    assert.expect(3);
+
+    await this.start();
+    const composer = this.env.models['mail.composer'].create();
+    await this.createComposerComponent(composer);
+    const file = await createFile({
+        content: 'hello, world',
+        contentType: 'text/plain',
+        name: 'text.txt',
+    });
+    await afterNextRender(() =>
+        inputFiles(
+            document.querySelector('.o_FileUploader_input'),
+            [file]
+        )
+    );
+    assert.containsOnce(
+        document.body,
+        '.o_Composer_attachmentList',
+        "should have an attachment list"
+    );
+    assert.containsOnce(
+        document.body,
+        '.o_Composer .o_Attachment',
+        "should have only one attachment"
+    );
+
+    await afterNextRender(() =>
+        document.querySelector('.o_Attachment_asideItemUnlink').click()
+    );
+    assert.containsNone(
+        document.body,
+        '.o_Composer .o_Attachment',
+        "should not have any attachment left after unlinking the only one"
+    );
+});
+
 QUnit.test('remove an uploading attachment', async function (assert) {
     assert.expect(4);
 
diff --git a/addons/mail/static/src/components/discuss/tests/discuss_inbox_tests.js b/addons/mail/static/src/components/discuss/tests/discuss_inbox_tests.js
index 00cd5d2c310..d547065f44d 100644
--- a/addons/mail/static/src/components/discuss/tests/discuss_inbox_tests.js
+++ b/addons/mail/static/src/components/discuss/tests/discuss_inbox_tests.js
@@ -44,6 +44,7 @@ QUnit.test('reply: discard on pressing escape', async function (assert) {
     });
     // message expected to be found in inbox
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'res.partner',
         needaction: true,
         needaction_partner_ids: [this.data.currentPartnerId],
@@ -143,6 +144,7 @@ QUnit.test('reply: discard on discard button click', async function (assert) {
     assert.expect(4);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'res.partner',
         needaction: true,
         needaction_partner_ids: [this.data.currentPartnerId],
@@ -183,6 +185,7 @@ QUnit.test('reply: discard on reply button toggle', async function (assert) {
     assert.expect(3);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'res.partner',
         needaction: true,
         needaction_partner_ids: [this.data.currentPartnerId],
@@ -218,6 +221,7 @@ QUnit.test('reply: discard on click away', async function (assert) {
     assert.expect(7);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'res.partner',
         needaction: true,
         needaction_partner_ids: [this.data.currentPartnerId],
@@ -284,6 +288,7 @@ QUnit.test('"reply to" composer should log note if message replied to is a note'
     assert.expect(6);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         is_discussion: false,
         model: 'res.partner',
         needaction: true,
@@ -336,6 +341,7 @@ QUnit.test('"reply to" composer should send message if message replied to is not
     assert.expect(6);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         is_discussion: true,
         model: 'res.partner',
         needaction: true,
@@ -388,6 +394,7 @@ QUnit.test('error notifications should not be shown in Inbox', async function (a
     assert.expect(3);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         id: 100,
         model: 'mail.channel',
         needaction: true,
@@ -422,6 +429,7 @@ QUnit.test('show subject of message in Inbox', async function (assert) {
     assert.expect(3);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'mail.channel', // random existing model
         needaction: true, // message_fetch domain
         needaction_partner_ids: [this.data.currentPartnerId], // not needed, for consistency
@@ -449,6 +457,7 @@ QUnit.test('show subject of message in history', async function (assert) {
     assert.expect(3);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         history_partner_ids: [3], // not needed, for consistency
         model: 'mail.channel', // random existing model
         subject: "Salutations, voyageur", // will be asserted in the test
@@ -509,6 +518,7 @@ QUnit.test('click on (non-channel/non-partner) origin thread link should redirec
     });
     this.data['some.model'] = { fields: {}, records: [{ id: 10 }] };
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'some.model',
         needaction: true,
         needaction_partner_ids: [this.data.currentPartnerId],
diff --git a/addons/mail/static/src/components/discuss/tests/discuss_moderation_tests.js b/addons/mail/static/src/components/discuss/tests/discuss_moderation_tests.js
index 7f1df69628c..04ca8b08e18 100644
--- a/addons/mail/static/src/components/discuss/tests/discuss_moderation_tests.js
+++ b/addons/mail/static/src/components/discuss/tests/discuss_moderation_tests.js
@@ -747,6 +747,7 @@ QUnit.test('as author, sent message accepted in moderated channel', async functi
         name: "general", // random name, will be asserted in the test
     });
     this.data['mail.message'].records.push({
+        body: "not empty",
         id: 100, // random unique id, will be referenced in the test
         model: 'mail.channel', // expected value to link message to channel
         moderation_status: 'pending_moderation', // message is expected to be pending
@@ -820,6 +821,7 @@ QUnit.test('as author, sent message rejected in moderated channel', async functi
         name: "general", // random name, will be asserted in the test
     });
     this.data['mail.message'].records.push({
+        body: "not empty",
         id: 100, // random unique id, will be referenced in the test
         model: 'mail.channel', // expected value to link message to channel
         moderation_status: 'pending_moderation', // message is expected to be pending
@@ -884,6 +886,7 @@ QUnit.test('as moderator, pending moderation message accessibility', async funct
         moderation: true, // channel must be moderated to test the feature
     });
     this.data['mail.message'].records.push({
+        body: "not empty",
         id: 100, // random unique id, will be referenced in the test
         model: 'mail.channel', // expected value to link message to channel
         moderation_status: 'pending_moderation', // message is expected to be pending
@@ -936,6 +939,7 @@ QUnit.test('as author, pending moderation message should appear in origin thread
     });
     this.data['mail.message'].records.push({
         author_id: this.data.currentPartnerId, // test as author of message
+        body: "not empty",
         id: 100, // random unique id, will be referenced in the test
         model: 'mail.channel', // expected value to link message to channel
         moderation_status: 'pending_moderation', // message is expected to be pending
@@ -983,6 +987,7 @@ QUnit.test('as moderator, new pending moderation message posted by someone else'
     // simulate receiving the message
     const messageData = {
         author_id: 10, // random id, different than current partner
+        body: "not empty",
         channel_ids: [], // server do NOT return channel_id of the message if pending moderation
         id: 1, // random unique id
         model: 'mail.channel', // expected value to link message to channel
@@ -1027,16 +1032,19 @@ QUnit.test('accept multiple moderation messages', async function (assert) {
     });
     this.data['mail.message'].records.push(
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
         },
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
         },
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
@@ -1100,16 +1108,19 @@ QUnit.test('accept multiple moderation messages after having accepted other mess
     });
     this.data['mail.message'].records.push(
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
         },
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
         },
         {
+            body: "not empty",
             model: 'mail.channel',
             moderation_status: 'pending_moderation',
             res_id: 20,
diff --git a/addons/mail/static/src/components/discuss/tests/discuss_tests.js b/addons/mail/static/src/components/discuss/tests/discuss_tests.js
index 67d52c33c88..989bb75235e 100644
--- a/addons/mail/static/src/components/discuss/tests/discuss_tests.js
+++ b/addons/mail/static/src/components/discuss/tests/discuss_tests.js
@@ -513,6 +513,7 @@ QUnit.test('sidebar: channel rendering with needaction counter', async function
     this.data['mail.channel'].records.push({ id: 20 });
     // expected needaction message
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [20], // link message to channel
         id: 100, // random unique id, useful to link notification
     });
@@ -1186,6 +1187,7 @@ QUnit.test('load single message from channel initially', async function (assert)
     // channel expected to be rendered, with a random unique id that will be referenced in the test
     this.data['mail.channel'].records.push({ id: 20 });
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [20],
         date: "2019-04-20 10:00:00",
         id: 100,
@@ -1554,6 +1556,7 @@ QUnit.test('load all messages from channel initially, less than fetch limit (29
     this.data['res.partner'].records.push({ id: 11 });
     for (let i = 28; i >= 0; i--) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
             date: "2019-04-20 10:00:00",
             model: 'mail.channel',
@@ -1613,6 +1616,7 @@ QUnit.test('load more messages from channel', async function (assert) {
     this.data['res.partner'].records.push({ id: 11 });
     for (let i = 0; i < 40; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
             date: "2019-04-20 10:00:00",
             model: 'mail.channel',
@@ -1684,6 +1688,7 @@ QUnit.test('auto-scroll to bottom of thread', async function (assert) {
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 1; i <= 25; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
             model: 'mail.channel',
             res_id: 20,
@@ -1719,6 +1724,7 @@ QUnit.test('load more messages from channel (auto-load on scroll)', async functi
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i < 40; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
             model: 'mail.channel',
             res_id: 20,
@@ -1784,6 +1790,7 @@ QUnit.test('new messages separator [REQUIRE FOCUS]', async function (assert) {
     });
     for (let i = 1; i <= 25; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
             id: 100 + i, // for setting proper value for seen_message_id
             model: 'mail.channel',
@@ -1886,6 +1893,7 @@ QUnit.test('restore thread scroll position', async function (assert) {
     this.data['mail.channel'].records.push({ id: 11 }, { id: 12 });
     for (let i = 1; i <= 25; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [11],
             model: 'mail.channel',
             res_id: 11,
@@ -1893,6 +1901,7 @@ QUnit.test('restore thread scroll position', async function (assert) {
     }
     for (let i = 1; i <= 24; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [12],
             model: 'mail.channel',
             res_id: 12,
@@ -2036,6 +2045,7 @@ QUnit.test('message origin redirect to channel', async function (assert) {
     this.data['mail.channel'].records.push({ id: 11 }, { id: 12 });
     this.data['mail.message'].records.push(
         {
+            body: "not empty",
             channel_ids: [11, 12],
             id: 100,
             model: 'mail.channel',
@@ -2043,6 +2053,7 @@ QUnit.test('message origin redirect to channel', async function (assert) {
             res_id: 11,
         },
         {
+            body: "not empty",
             channel_ids: [11, 12],
             id: 101,
             model: 'mail.channel',
@@ -2245,6 +2256,7 @@ QUnit.test('redirect to author (open chat)', async function (assert) {
     this.data['mail.message'].records.push(
         {
             author_id: 7,
+            body: "not empty",
             channel_ids: [1],
             id: 100,
             model: 'mail.channel',
@@ -2483,6 +2495,7 @@ QUnit.test('inbox: mark all messages as read', async function (assert) {
     this.data['mail.message'].records.push(
         // first expected message
         {
+            body: "not empty",
             channel_ids: [20], // link message to channel
             id: 100, // random unique id, useful to link notification
             // needaction needs to be set here for message_fetch domain, because
@@ -2491,6 +2504,7 @@ QUnit.test('inbox: mark all messages as read', async function (assert) {
         },
         // second expected message
         {
+            body: "not empty",
             channel_ids: [20], // link message to channel
             id: 101, // random unique id, useful to link notification
             // needaction needs to be set here for message_fetch domain, because
@@ -2586,8 +2600,8 @@ QUnit.test('starred: unstar all', async function (assert) {
 
     // messages expected to be starred
     this.data['mail.message'].records.push(
-        { starred_partner_ids: [this.data.currentPartnerId] },
-        { starred_partner_ids: [this.data.currentPartnerId] }
+        { body: "not empty", starred_partner_ids: [this.data.currentPartnerId] },
+        { body: "not empty", starred_partner_ids: [this.data.currentPartnerId] }
     );
     await this.start({
         discuss: {
@@ -2647,6 +2661,7 @@ QUnit.test('toggle_star message', async function (assert) {
     // with a random unique id, will be referenced in the test
     this.data['mail.channel'].records.push({ id: 20 });
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [20],
         id: 100,
         model: 'mail.channel',
@@ -3176,6 +3191,7 @@ QUnit.test('rendering of inbox message', async function (assert) {
     assert.expect(7);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         model: 'res.partner', // random existing model
         needaction: true, // for message_fetch domain
         needaction_partner_ids: [this.data.currentPartnerId], // for consistency
@@ -3228,6 +3244,7 @@ QUnit.test('mark channel as seen on last message visible [REQUIRE FOCUS]', async
     // and a random unique id that will be referenced in the test
     this.data['mail.channel'].records.push({ id: 10, message_unread_counter: 1 });
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [10],
         model: 'mail.channel',
         res_id: 10,
@@ -3318,6 +3335,7 @@ QUnit.test('receive new needaction messages', async function (assert) {
     // simulate receiving a new needaction message
     await afterNextRender(() => {
         const data = {
+            body: "not empty",
             id: 100,
             needaction_partner_ids: [3],
             model: 'res.partner',
@@ -3359,6 +3377,7 @@ QUnit.test('receive new needaction messages', async function (assert) {
     // simulate receiving another new needaction message
     await afterNextRender(() => {
         const data2 = {
+            body: "not empty",
             id: 101,
             needaction_partner_ids: [3],
             model: 'res.partner',
@@ -3533,6 +3552,7 @@ QUnit.test('load recent messages from thread (already loaded some old messages)'
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i < 50; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20], // id of related channel
             id: 100 + i, // random unique id, will be referenced in the test
             model: 'mail.channel', // expected value to link message to channel
@@ -3610,6 +3630,7 @@ QUnit.test('messages marked as read move to "History" mailbox', async function (
     // expected messages
     this.data['mail.message'].records.push(
         {
+            body: "not empty",
             id: 100, // random unique id, useful to link notification
             model: 'mail.channel', // value to link message to channel
             // needaction needs to be set here for message_fetch domain, because
@@ -3618,6 +3639,7 @@ QUnit.test('messages marked as read move to "History" mailbox', async function (
             res_id: 20, // id of related channel
         },
         {
+            body: "not empty",
             id: 101, // random unique id, useful to link notification
             model: 'mail.channel', // value to link message to channel
             // needaction needs to be set here for message_fetch domain, because
@@ -3734,11 +3756,13 @@ QUnit.test('mark a single message as read should only move this message to "Hist
 
     this.data['mail.message'].records.push(
         {
+            body: "not empty",
             id: 1,
             needaction: true,
             needaction_partner_ids: [this.data.currentPartnerId],
         },
         {
+            body: "not empty",
             id: 2,
             needaction: true,
             needaction_partner_ids: [this.data.currentPartnerId],
@@ -3856,6 +3880,7 @@ QUnit.test('all messages in "Inbox" in "History" after marked all as read', asyn
     for (let id = messageOffset; id < messageOffset + 40; id++) {
         // message expected to be found in Inbox
         this.data['mail.message'].records.push({
+            body: "not empty",
             id, // will be used to link notification to message
             // needaction needs to be set here for message_fetch domain, because
             // mocked models don't have computed fields
diff --git a/addons/mail/static/src/components/message/message_tests.js b/addons/mail/static/src/components/message/message_tests.js
index bf27d71fdb5..a880169967b 100644
--- a/addons/mail/static/src/components/message/message_tests.js
+++ b/addons/mail/static/src/components/message/message_tests.js
@@ -708,7 +708,7 @@ QUnit.test('only show messaging seen indicator if authored by me, after last see
 });
 
 QUnit.test('allow attachment delete on authored message', async function (assert) {
-    assert.expect(3);
+    assert.expect(5);
 
     await this.start();
     const message = this.env.models['mail.message'].create({
@@ -735,6 +735,20 @@ QUnit.test('allow attachment delete on authored message', async function (assert
     );
 
     await afterNextRender(() => document.querySelector('.o_Attachment_asideItemUnlink').click());
+    assert.containsOnce(
+        document.body,
+        '.o_AttachmentDeleteConfirmDialog',
+        "An attachment delete confirmation dialog should have been opened"
+    );
+    assert.strictEqual(
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_mainText').textContent,
+        `Do you really want to delete "BLAH"?`,
+        "Confirmation dialog should contain the attachment delete confirmation text"
+    );
+
+    await afterNextRender(() =>
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_confirmButton').click()
+    );
     assert.containsNone(
         document.body,
         '.o_Attachment',
diff --git a/addons/mail/static/src/components/message_list/message_list.js b/addons/mail/static/src/components/message_list/message_list.js
index b7332514141..708af154cb8 100644
--- a/addons/mail/static/src/components/message_list/message_list.js
+++ b/addons/mail/static/src/components/message_list/message_list.js
@@ -107,7 +107,7 @@ class MessageList extends Component {
      * Because of this, the scroll position must be changed when whole UI
      * is rendered. To make this simpler, this is done when <ThreadView/>
      * component is patched. This is acceptable when <ThreadView/> has a
-     * fixed height, which is the case for the moment.
+     * fixed height, which is the case for the moment. task-2358066
      */
     async adjustFromComponentHints() {
         if (!this.threadView) {
@@ -418,9 +418,6 @@ class MessageList extends Component {
         if (this.props.order === 'asc' && this.props.hasScrollAdjust) {
             this.el.scrollTop = this.el.scrollHeight - scrollHeight + scrollTop;
         }
-        this.env.messagingBus.trigger('o-component-message-list-more-messages-loaded', {
-            threadViewer: this.threadView.threadViewer,
-        });
         this.threadView.markComponentHintProcessed(hint);
     }
 
diff --git a/addons/mail/static/src/components/message_list/message_list.xml b/addons/mail/static/src/components/message_list/message_list.xml
index bff87fba3d2..4f8670a64d1 100644
--- a/addons/mail/static/src/components/message_list/message_list.xml
+++ b/addons/mail/static/src/components/message_list/message_list.xml
@@ -49,36 +49,38 @@
                     </div>
                 </t>
                 <t t-foreach="orderedMessages" t-as="message" t-key="message.localId">
-                    <t t-set="message_day" t-value="getDateDay(message)"/>
-                    <t t-if="current_day !== message_day">
-                        <div class="o_MessageList_separator o_MessageList_separatorDate o_MessageList_item">
-                            <hr class="o_MessageList_separatorLine"/><span class="o_MessageList_separatorLabel o_MessageList_separatorLabelDate"><t t-esc="message_day"/></span><hr class="o_MessageList_separatorLine"/>
-                            <t t-set="current_day" t-value="message_day"/>
-                            <t t-set="isMessageSquashed" t-value="false"/>
-                        </div>
-                    </t>
-                    <t t-else="">
-                        <t t-set="isMessageSquashed" t-value="shouldMessageBeSquashed(prev_message, message)"/>
-                    </t>
-                    <Message
-                        class="o_MessageList_item o_MessageList_message"
-                        t-att-class="{
-                            'o-has-message-selection': props.selectedMessageLocalId,
-                        }"
-                        hasMarkAsReadIcon="props.haveMessagesMarkAsReadIcon"
-                        hasCheckbox="props.hasMessageCheckbox"
-                        hasReplyIcon="props.haveMessagesReplyIcon"
-                        isSelected="props.selectedMessageLocalId === message.localId"
-                        isSquashed="isMessageSquashed"
-                        messageLocalId="message.localId"
-                        threadViewLocalId="threadView.localId"
-                        t-ref="{{ message.localId }}"
-                    />
-                    <t t-set="prev_message" t-value="message"/>
-                    <t t-if="threadView.thread.model === 'mail.channel' and threadView.thread.localMessageUnreadCounter > 0 and threadView.thread.lastSeenByCurrentPartnerMessageId === message.id">
-                        <div class="o_MessageList_separator o_MessageList_separatorNewMessages o_MessageList_item" t-att-class="{ 'o-disable-animation': env.disableAnimation }" t-transition="fade">
-                            <hr class="o_MessageList_separatorLine o_MessageList_separatorLineNewMessages"/><span class="o_MessageList_separatorLabel o_MessageList_separatorLabelNewMessages">New messages</span>
-                        </div>
+                    <t t-if="!message.isEmpty">
+                        <t t-set="message_day" t-value="getDateDay(message)"/>
+                        <t t-if="current_day !== message_day">
+                            <div class="o_MessageList_separator o_MessageList_separatorDate o_MessageList_item">
+                                <hr class="o_MessageList_separatorLine"/><span class="o_MessageList_separatorLabel o_MessageList_separatorLabelDate"><t t-esc="message_day"/></span><hr class="o_MessageList_separatorLine"/>
+                                <t t-set="current_day" t-value="message_day"/>
+                                <t t-set="isMessageSquashed" t-value="false"/>
+                            </div>
+                        </t>
+                        <t t-else="">
+                            <t t-set="isMessageSquashed" t-value="shouldMessageBeSquashed(prev_message, message)"/>
+                        </t>
+                        <Message
+                            class="o_MessageList_item o_MessageList_message"
+                            t-att-class="{
+                                'o-has-message-selection': props.selectedMessageLocalId,
+                            }"
+                            hasMarkAsReadIcon="props.haveMessagesMarkAsReadIcon"
+                            hasCheckbox="props.hasMessageCheckbox"
+                            hasReplyIcon="props.haveMessagesReplyIcon"
+                            isSelected="props.selectedMessageLocalId === message.localId"
+                            isSquashed="isMessageSquashed"
+                            messageLocalId="message.localId"
+                            threadViewLocalId="threadView.localId"
+                            t-ref="{{ message.localId }}"
+                        />
+                        <t t-set="prev_message" t-value="message"/>
+                        <t t-if="threadView.thread.model === 'mail.channel' and threadView.thread.localMessageUnreadCounter > 0 and threadView.thread.lastSeenByCurrentPartnerMessageId === message.id">
+                            <div class="o_MessageList_separator o_MessageList_separatorNewMessages o_MessageList_item" t-att-class="{ 'o-disable-animation': env.disableAnimation }" t-transition="fade">
+                                <hr class="o_MessageList_separatorLine o_MessageList_separatorLineNewMessages"/><span class="o_MessageList_separatorLabel o_MessageList_separatorLabelNewMessages">New messages</span>
+                            </div>
+                        </t>
                     </t>
                 </t>
                 <!-- LOADING (if order desc)-->
diff --git a/addons/mail/static/src/components/moderation_ban_dialog/moderation_ban_dialog.js b/addons/mail/static/src/components/moderation_ban_dialog/moderation_ban_dialog.js
index 2880c1747bb..c7a5ed71a65 100644
--- a/addons/mail/static/src/components/moderation_ban_dialog/moderation_ban_dialog.js
+++ b/addons/mail/static/src/components/moderation_ban_dialog/moderation_ban_dialog.js
@@ -3,7 +3,9 @@ odoo.define('mail/static/src/components/moderation_ban_dialog/moderation_ban_dia
 
 const useStore = require('mail/static/src/component_hooks/use_store/use_store.js');
 
-const Dialog = require('web.OwlDialog');
+const components = {
+    Dialog: require('web.OwlDialog'),
+};
 
 const { Component } = owl;
 const { useRef } = owl.hooks;
@@ -71,7 +73,7 @@ class ModerationBanDialog extends Component {
 }
 
 Object.assign(ModerationBanDialog, {
-    components: { Dialog },
+    components,
     props: {
         messageLocalIds: {
             type: Array,
diff --git a/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.js b/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.js
index 5f6a906df46..87e4ec84f94 100644
--- a/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.js
+++ b/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.js
@@ -3,7 +3,9 @@ odoo.define('mail/static/src/components/moderation_discard_dialog/moderation_dis
 
 const useStore = require('mail/static/src/component_hooks/use_store/use_store.js');
 
-const Dialog = require('web.OwlDialog');
+const components = {
+    Dialog: require('web.OwlDialog'),
+};
 
 const { Component } = owl;
 const { useRef } = owl.hooks;
@@ -38,7 +40,7 @@ class ModerationDiscardDialog extends Component {
     /**
      * @returns {string}
      */
-    getText() {
+    getBody() {
         if (this.messages.length === 1) {
             return this.env._t("You are going to discard 1 message.");
         }
@@ -60,7 +62,7 @@ class ModerationDiscardDialog extends Component {
     /**
      * @returns {string}
      */
-    get CONFIRMATION() {
+    getTitle() {
         return this.env._t("Confirmation");
     }
 
@@ -86,7 +88,7 @@ class ModerationDiscardDialog extends Component {
 }
 
 Object.assign(ModerationDiscardDialog, {
-    components: { Dialog },
+    components,
     props: {
         messageLocalIds: {
             type: Array,
diff --git a/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.xml b/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.xml
index 1ff759bc53a..58dbc14dc5c 100644
--- a/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.xml
+++ b/addons/mail/static/src/components/moderation_discard_dialog/moderation_discard_dialog.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <templates xml:space="preserve">
     <t t-name="mail.ModerationDiscardDialog" owl="1">
-        <Dialog contentClass="'o_ModerationDiscardDialog'" title="CONFIRMATION" size="'medium'" t-ref="dialog">
-            <p t-esc="getText()"/>
+        <Dialog contentClass="'o_ModerationDiscardDialog'" title="getTitle()" size="'medium'" t-ref="dialog">
+            <p t-esc="getBody()"/>
             <p>Do you confirm the action?</p>
             <t t-set-slot="buttons">
                 <button class="o-discard btn btn-primary" t-on-click="_onClickDiscard">Discard</button>
diff --git a/addons/mail/static/src/components/moderation_reject_dialog/moderation_reject_dialog.js b/addons/mail/static/src/components/moderation_reject_dialog/moderation_reject_dialog.js
index 675e3e48d8e..e488aea4ea7 100644
--- a/addons/mail/static/src/components/moderation_reject_dialog/moderation_reject_dialog.js
+++ b/addons/mail/static/src/components/moderation_reject_dialog/moderation_reject_dialog.js
@@ -3,7 +3,9 @@ odoo.define('mail/static/src/components/moderation_reject_dialog/moderation_reje
 
 const useStore = require('mail/static/src/component_hooks/use_store/use_store.js');
 
-const Dialog = require('web.OwlDialog');
+const components = {
+    Dialog: require('web.OwlDialog'),
+};
 
 const { Component, useState } = owl;
 const { useRef } = owl.hooks;
@@ -81,7 +83,7 @@ class ModerationRejectDialog extends Component {
 }
 
 Object.assign(ModerationRejectDialog, {
-    components: { Dialog },
+    components,
     props: {
         messageLocalIds: {
             type: Array,
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 2bf4c08a7a8..5230f252e03 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
@@ -101,6 +101,7 @@ QUnit.test('message list desc order', async function (assert) {
 
     for (let i = 0; i <= 60; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [100],
             model: 'mail.channel',
             res_id: 100,
@@ -172,6 +173,7 @@ QUnit.test('message list asc order', async function (assert) {
 
     for (let i = 0; i <= 60; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [100],
             model: 'mail.channel',
             res_id: 100,
@@ -389,6 +391,7 @@ QUnit.test('show message subject if thread is mailing channel', async function (
     assert.expect(3);
 
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [100],
         model: 'mail.channel',
         res_id: 100,
@@ -717,6 +720,7 @@ QUnit.test('basic rendering of canceled notification', async function (assert) {
     this.data['mail.channel'].records.push({ id: 11 });
     this.data['res.partner'].records.push({ id: 12, name: "Someone" });
     this.data['mail.message'].records.push({
+        body: "not empty",
         channel_ids: [11],
         id: 10,
         message_type: 'email',
@@ -817,6 +821,7 @@ QUnit.test('should scroll to bottom on receiving new message if the list is init
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i <= 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
         });
     }
@@ -887,6 +892,7 @@ QUnit.test('should not scroll on receiving new message if the list is initially
     this.data['mail.channel'].records.push({ id: 20 });
     for (let i = 0; i <= 10; i++) {
         this.data['mail.message'].records.push({
+            body: "not empty",
             channel_ids: [20],
         });
     }
@@ -952,6 +958,186 @@ QUnit.test('should not scroll on receiving new message if the list is initially
     );
 });
 
+QUnit.test("delete all attachments of message without content should no longer display the message", async function (assert) {
+    assert.expect(2);
+
+    this.data['ir.attachment'].records.push({
+        id: 143,
+        mimetype: 'text/plain',
+        name: "Blah.txt",
+    });
+    this.data['mail.channel'].records.push({ id: 11 });
+    this.data['mail.message'].records.push(
+        {
+            attachment_ids: [143],
+            channel_ids: [11],
+            id: 101,
+        }
+    );
+    await this.start();
+    const threadViewer = this.env.models['mail.thread_viewer'].create({
+        hasThreadView: true,
+        thread: [['insert', { id: 11, model: 'mail.channel' }]],
+    });
+    // wait for messages of the thread to be loaded
+    await this.afterEvent({
+        eventName: 'o-thread-view-hint-processed',
+        func: () => {
+            this.createThreadViewComponent(threadViewer.threadView);
+        },
+        message: "thread become loaded with messages",
+        predicate: ({ hint, threadViewer }) => {
+            return (
+                hint.type === 'messages-loaded' &&
+                threadViewer.thread.model === 'mail.channel' &&
+                threadViewer.thread.id === 11
+            );
+        },
+    });
+    assert.containsOnce(
+        document.body,
+        '.o_Message',
+        "there should be 1 message displayed initially"
+    );
+
+    await afterNextRender(() => {
+        document.querySelector(`.o_Attachment[data-attachment-local-id="${
+            this.env.models['mail.attachment'].findFromIdentifyingData({ id: 143 }).localId
+        }"] .o_Attachment_asideItemUnlink`).click();
+    });
+    await afterNextRender(() =>
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_confirmButton').click()
+    );
+    assert.containsNone(
+        document.body,
+        '.o_Message',
+        "message should no longer be displayed after removing all its attachments (empty content)"
+    );
+});
+
+QUnit.test('delete all attachments of a message with some text content should still keep it displayed', async function (assert) {
+    assert.expect(2);
+
+    this.data['ir.attachment'].records.push({
+        id: 143,
+        mimetype: 'text/plain',
+        name: "Blah.txt",
+    });
+    this.data['mail.channel'].records.push({ id: 11 });
+    this.data['mail.message'].records.push(
+        {
+            attachment_ids: [143],
+            body: "Some content",
+            channel_ids: [11],
+            id: 101,
+        },
+    );
+    await this.start();
+    const threadViewer = this.env.models['mail.thread_viewer'].create({
+        hasThreadView: true,
+        thread: [['insert', { id: 11, model: 'mail.channel' }]],
+    });
+    // wait for messages of the thread to be loaded
+    await this.afterEvent({
+        eventName: 'o-thread-view-hint-processed',
+        func: () => {
+            this.createThreadViewComponent(threadViewer.threadView);
+        },
+        message: "thread become loaded with messages",
+        predicate: ({ hint, threadViewer }) => {
+            return (
+                hint.type === 'messages-loaded' &&
+                threadViewer.thread.model === 'mail.channel' &&
+                threadViewer.thread.id === 11
+            );
+        },
+    });
+    assert.containsOnce(
+        document.body,
+        '.o_Message',
+        "there should be 1 message displayed initially"
+    );
+
+    await afterNextRender(() => {
+        document.querySelector(`.o_Attachment[data-attachment-local-id="${
+            this.env.models['mail.attachment'].findFromIdentifyingData({ id: 143 }).localId
+        }"] .o_Attachment_asideItemUnlink`).click();
+    });
+    await afterNextRender(() =>
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_confirmButton').click()
+    );
+    assert.containsOnce(
+        document.body,
+        '.o_Message',
+        "message should still be displayed after removing its attachments (non-empty content)"
+    );
+});
+
+QUnit.test('delete all attachments of a message with tracking fields should still keep it displayed', async function (assert) {
+    assert.expect(2);
+
+    this.data['ir.attachment'].records.push({
+        id: 143,
+        mimetype: 'text/plain',
+        name: "Blah.txt",
+    });
+    this.data['mail.channel'].records.push({ id: 11 });
+    this.data['mail.message'].records.push(
+        {
+            attachment_ids: [143],
+            channel_ids: [11],
+            id: 101,
+            tracking_value_ids: [6]
+        },
+    );
+    this.data['mail.tracking.value'].records.push({
+        changed_field: "Name",
+        field_type: "char",
+        id: 6,
+        new_value: "New name",
+        old_value: "Old name",
+    });
+    await this.start();
+    const threadViewer = this.env.models['mail.thread_viewer'].create({
+        hasThreadView: true,
+        thread: [['insert', { id: 11, model: 'mail.channel' }]],
+    });
+    // wait for messages of the thread to be loaded
+    await this.afterEvent({
+        eventName: 'o-thread-view-hint-processed',
+        func: () => {
+            this.createThreadViewComponent(threadViewer.threadView);
+        },
+        message: "thread become loaded with messages",
+        predicate: ({ hint, threadViewer }) => {
+            return (
+                hint.type === 'messages-loaded' &&
+                threadViewer.thread.model === 'mail.channel' &&
+                threadViewer.thread.id === 11
+            );
+        },
+    });
+    assert.containsOnce(
+        document.body,
+        '.o_Message',
+        "there should be 1 message displayed initially"
+    );
+
+    await afterNextRender(() => {
+        document.querySelector(`.o_Attachment[data-attachment-local-id="${
+            this.env.models['mail.attachment'].findFromIdentifyingData({ id: 143 }).localId
+        }"] .o_Attachment_asideItemUnlink`).click();
+    });
+    await afterNextRender(() =>
+        document.querySelector('.o_AttachmentDeleteConfirmDialog_confirmButton').click()
+    );
+    assert.containsOnce(
+        document.body,
+        '.o_Message',
+        "message should still be displayed after removing its attachments (non-empty content)"
+    );
+});
+
 });
 });
 });
diff --git a/addons/mail/static/src/models/message/message.js b/addons/mail/static/src/models/message/message.js
index 953c3c29385..8b4029b4b48 100644
--- a/addons/mail/static/src/models/message/message.js
+++ b/addons/mail/static/src/models/message/message.js
@@ -401,6 +401,17 @@ function factory(dependencies) {
             return inlineBody.toLowerCase() === this.subtype_description.toLowerCase();
         }
 
+        /**
+         * @private
+         */
+        _computeIsEmpty() {
+            return (
+                (!this.body || htmlToTextContentInline(this.body) === '') &&
+                this.attachments.length === 0 &&
+                this.tracking_value_ids.length === 0
+            );
+        }
+
         /**
          * @private
          * @returns {boolean}
@@ -551,6 +562,19 @@ function factory(dependencies) {
                 'subtype_description',
             ],
         }),
+        /**
+         * Determine whether the message has to be considered empty or not.
+         *
+         * An empty message has no text, no attachment and no tracking value.
+         */
+        isEmpty: attr({
+            compute: '_computeIsEmpty',
+            dependencies: [
+                'attachments',
+                'body',
+                'tracking_value_ids',
+            ],
+        }),
         isModeratedByCurrentPartner: attr({
             compute: '_computeIsModeratedByCurrentPartner',
             default: false,
diff --git a/addons/mail/static/src/widgets/form_renderer/form_renderer_tests.js b/addons/mail/static/src/widgets/form_renderer/form_renderer_tests.js
index 8817664497c..e57317a7496 100644
--- a/addons/mail/static/src/widgets/form_renderer/form_renderer_tests.js
+++ b/addons/mail/static/src/widgets/form_renderer/form_renderer_tests.js
@@ -463,7 +463,7 @@ QUnit.test('basic chatter rendering without messages', async function (assert) {
 QUnit.test('chatter updating', async function (assert) {
     assert.expect(3);
 
-    this.data['mail.message'].records.push({ model: 'res.partner', res_id: 12 });
+    this.data['mail.message'].records.push({ body: "not empty", model: 'res.partner', res_id: 12 });
     this.data['res.partner'].records.push(
         { display_name: "first partner", id: 11 },
         { display_name: "second partner", id: 12 }
diff --git a/addons/mail/static/tests/helpers/mock_models.js b/addons/mail/static/tests/helpers/mock_models.js
index 83ac74008a3..59bf06b72b6 100644
--- a/addons/mail/static/tests/helpers/mock_models.js
+++ b/addons/mail/static/tests/helpers/mock_models.js
@@ -136,6 +136,7 @@ class MockModels {
                     res_model_name: { string: "Res Model Name", type: 'char' },
                     starred_partner_ids: { string: "Favorited By", type: 'many2many', relation: 'res.partner' },
                     subject: { string: "Subject", type: 'char' },
+                    tracking_value_ids: { relation: 'mail.tracking.value', string: "Tracking values", type: 'one2many' },
                 },
                 records: [],
             },
@@ -177,6 +178,15 @@ class MockModels {
                 },
                 records: [],
             },
+            'mail.tracking.value': {
+                fields: {
+                    changed_field: { string: 'Changed field', type: 'char' },
+                    field_type: { string: 'Field type', type: 'char' },
+                    new_value: { string: 'New value', type: 'char' },
+                    old_value: { string: 'Old value', type: 'char' },
+                },
+                records: [],
+            },
             'res.country': {
                 fields: {
                     code: { string: "Code", type: 'char' },