diff --git a/addons/mail/static/src/scss/composer.scss b/addons/mail/static/src/scss/composer.scss
index 9dbdf8fde89..e7f7eb98d3b 100644
--- a/addons/mail/static/src/scss/composer.scss
+++ b/addons/mail/static/src/scss/composer.scss
@@ -15,7 +15,6 @@
 .o_thread_composer {
     flex: 0 0 auto;
     display: flex;
-    margin: 1px 0;
     border-top: none;
     background: theme-color('light');
 
@@ -69,11 +68,6 @@
         .o_composer_button_full_composer {
             @include o-position-absolute(auto, 0);
         }
-        @include media-breakpoint-down(sm) {
-            .o_composer_button_send {
-                color: $o-brand-primary;
-            }
-        }
 
         .o_mail_emoji_container {
             padding: 0 $o-mail-chatter-gap $o-mail-chatter-gap 0;
@@ -120,6 +114,12 @@
             .o_mail_emoji_container {
                 margin: 0 -$o-mail-chatter-gap;
             }
+
+            @include media-breakpoint-down(sm) {
+                .o_composer_button_send {
+                    color: $o-brand-primary;
+                }
+            }
         }
 
         .o_composer, .o_composer_subject {
@@ -243,7 +243,7 @@
                 }
             }
         }
-        .o_composer_button_send, .o_chatter_avatar {
+        .o_composer_send .o_composer_button_send, .o_chatter_avatar {
             display: none !important;
         }
     }
diff --git a/addons/mail/static/src/xml/composer.xml b/addons/mail/static/src/xml/composer.xml
index f405617affa..83ce49a7021 100644
--- a/addons/mail/static/src/xml/composer.xml
+++ b/addons/mail/static/src/xml/composer.xml
@@ -19,7 +19,7 @@
                     <div class="o_chatter_composer_tools">
                         <button tabindex="4" class="btn btn-secondary fa fa-smile-o o_composer_button_emoji" type="button" data-toggle="popover" title="Emojis" aria-label="Emojis"/>
                         <button tabindex="5" class="btn btn-secondary fa fa-paperclip o_composer_button_add_attachment" type="button" aria-label="Add attachment" title="Add attachment"/>
-                        <button t-if="widget.options.isMobile" tabindex="3" class="btn btn-secondary fa fa-paper-plane-o o_composer_button_send" type="button" title="Send" aria-label="Send"/>
+                        <button t-if="widget.options.isMobile" tabindex="3" t-attf-class="btn #{widget.isMini ? 'btn-primary' : 'btn-secondary'} fa fa-paper-plane-o o_composer_button_send" type="button" title="Send" aria-label="Send"/>
                     </div>
                 </div>
              </div>