diff --git a/addons/mail/static/src/widgets/form_renderer/form_renderer.js b/addons/mail/static/src/widgets/form_renderer/form_renderer.js
index 14dcd00929e..cd788990e63 100644
--- a/addons/mail/static/src/widgets/form_renderer/form_renderer.js
+++ b/addons/mail/static/src/widgets/form_renderer/form_renderer.js
@@ -1,6 +1,7 @@
 /** @odoo-module **/
 
 import { ChatterContainer } from '@mail/components/chatter_container/chatter_container';
+import { AttachmentViewer } from '@mail/widgets/attachment_viewer/attachment_viewer';
 
 import dom from 'web.dom';
 import FormRenderer from 'web.FormRenderer';
@@ -47,6 +48,7 @@ FormRenderer.include({
          * when applying the rendering into the DOM.
          */
         this.chatterContainerTargetPlaceholder = undefined;
+        this.attachmentViewer = undefined;
         this.attachmentViewerTarget = undefined;
         if (this.hasAttachmentViewerFeature) {
             this.attachmentViewerTarget = document.createElement("div");
@@ -238,12 +240,51 @@ FormRenderer.include({
         }
     },
     /**
-     * @abstract
      * @private
      * @param {OdooEvent} ev
      * @param {Object} ev.data
      * @param {Attachment[]} ev.data.attachments
      * @param {Thread} ev.data.thread
      */
-    _onChatterRendered(ev) {},
+    _onChatterRendered(ev) {
+        if (!this.hasAttachmentViewer()) {
+            if (this.attachmentViewer) {
+                this.attachmentViewer.destroy();
+                this.attachmentViewer = undefined;
+                this._interchangeChatter();
+            }
+            return;
+        }
+        var self = this;
+        const thread = ev.data.thread;
+        const attachments = thread.attachmentsInWebClientView;
+        if (attachments.length || this.attachmentViewer) {
+            if (this.attachmentViewer) {
+                // FIXME should be improved : what if somehow an attachment is replaced in a thread ?
+                if (
+                    this.attachmentViewer.thread !== thread ||
+                    this.attachmentViewer.attachments.length !== attachments.length
+                ) {
+                    if (attachments.length) {
+                        this.attachmentViewer.updateContents(thread);
+                    }
+                } else {
+                    // The attachmentViewer lose its event listeners when it is reused,
+                    // we just need to reregister them.
+                    if (this.attachmentViewer.$el) {
+                        this.attachmentViewer._undelegateEvents();
+                        this.attachmentViewer._delegateEvents();
+                    }
+                }
+                this.trigger_up('preview_attachment_validation');
+                this._updateChatterContainerTarget();
+            } else {
+                this.attachmentViewer = new AttachmentViewer(this, thread);
+                this.attachmentViewer.appendTo($(this.attachmentViewerTarget)).then(function () {
+                    self.trigger_up('preview_attachment_validation');
+                    self._interchangeChatter();
+                });
+            }
+        }
+    },
 });