diff --git a/addons/mail/static/src/composer/composer.js b/addons/mail/static/src/composer/composer.js
index ccb5df65041..0cca26d5663 100644
--- a/addons/mail/static/src/composer/composer.js
+++ b/addons/mail/static/src/composer/composer.js
@@ -40,6 +40,7 @@ export class Composer extends Component {
     };
     static defaultProps = {
         mode: "normal",
+        className: "",
     }; // mode = compact, normal, extended
     static props = [
         "composer",
@@ -53,6 +54,7 @@ export class Composer extends Component {
         "dropzoneRef?",
         "messageEdition?",
         "messageComponent?",
+        "className?",
     ];
     static template = "mail.Composer";
 
diff --git a/addons/mail/static/src/composer/composer.xml b/addons/mail/static/src/composer/composer.xml
index da632acf4e4..c3707c915f1 100644
--- a/addons/mail/static/src/composer/composer.xml
+++ b/addons/mail/static/src/composer/composer.xml
@@ -11,7 +11,7 @@
                     'px-3 py-4 o-extended': extended,
                     'p-3': normal,
                     'o-hasSelfAvatar px-3': !env.inChatWindow and thread,
-                }">
+                }" t-attf-class="{{ props.className }}">
             <div class="o-mail-Composer-sidebarMain flex-shrink-0" t-if="!compact">
                 <img class="o-mail-Composer-avatar mt-1 rounded-circle" t-att-src="threadService.avatarUrl(store.self, props.composer.thread)" alt="Avatar of user"/>
             </div>
diff --git a/addons/mail/static/src/web/chatter.xml b/addons/mail/static/src/web/chatter.xml
index afa376ff750..fed448f8f44 100644
--- a/addons/mail/static/src/web/chatter.xml
+++ b/addons/mail/static/src/web/chatter.xml
@@ -80,7 +80,7 @@
             <t t-else="" t-set="placeholder">Log an internal note...</t>
             <t t-set="type" t-value="state.thread.composer.type === 'message' ? 'message' : 'note'"/>
             <SuggestedRecipientsList t-if="props.hasFollowers and state.thread.composer.type !== 'note'" className="'px-3'" styleString="'margin-left:48px;'" thread="state.thread"/>
-            <Composer composer="state.thread.composer" autofocus="true" mode="'extended'" onPostCallback.bind="onPostCallback" placeholder="placeholder" dropzoneRef="rootRef"/>
+            <Composer composer="state.thread.composer" autofocus="true" mode="'extended'" onPostCallback.bind="onPostCallback" placeholder="placeholder" dropzoneRef="rootRef" className="state.thread.composer.type === 'message' ? 'pt-0' : ''"/>
             <hr/>
         </t>
         <div class="o-mail-Chatter-scrollable overflow-auto" t-ref="scrollable">