diff --git a/addons/mail/static/src/js/document_viewer.js b/addons/mail/static/src/js/document_viewer.js
index 8a183ef6ec3..d03b4811c76 100644
--- a/addons/mail/static/src/js/document_viewer.js
+++ b/addons/mail/static/src/js/document_viewer.js
@@ -20,6 +20,7 @@ var DocumentViewer = Widget.extend({
         'click .o_rotate': '_onRotate',
         'click .o_zoom_in': '_onZoomIn',
         'click .o_zoom_out': '_onZoomOut',
+        'click .o_zoom_reset': '_onZoomReset',
         'click .o_close_btn, .o_viewer_img_wrapper': '_onClose',
         'click .o_print_btn': '_onPrint',
         'DOMMouseScroll .o_viewer_content': '_onScroll',    // Firefox
@@ -141,6 +142,7 @@ var DocumentViewer = Widget.extend({
             this.$('.o_viewer_img').css('transform', this._getTransform(scale, this.angle || 0));
             this.scale = scale;
         }
+        this.$('.o_zoom_reset').add('.o_zoom_out').toggleClass('disabled', scale === 1);
     },
 
     //--------------------------------------------------------------------------
@@ -335,6 +337,15 @@ var DocumentViewer = Widget.extend({
         var scale = this.scale - ZOOM_STEP;
         this._zoom(scale);
     },
+    /**
+     * @private
+     * @param {MouseEvent} e
+     */
+    _onZoomReset: function (e) {
+        e.preventDefault();
+        this.$('.o_viewer_zoomer').css("transform", "");
+        this._zoom(1);
+    },
 });
 return DocumentViewer;
 });
diff --git a/addons/mail/static/src/less/composer.less b/addons/mail/static/src/less/composer.less
index 671dd6148bf..8a5fb7891ee 100644
--- a/addons/mail/static/src/less/composer.less
+++ b/addons/mail/static/src/less/composer.less
@@ -342,6 +342,11 @@
             background-color: fade(black,60%);
             color: white;
         }
+
+        &.disabled {
+            color: @gray-light;
+            background: none;
+        }
     }
 
     .o_viewer_content {
diff --git a/addons/mail/static/src/xml/thread.xml b/addons/mail/static/src/xml/thread.xml
index 0f04e5c0e8e..be2a81b4e92 100644
--- a/addons/mail/static/src/xml/thread.xml
+++ b/addons/mail/static/src/xml/thread.xml
@@ -46,12 +46,13 @@
             <div t-if="widget.activeAttachment.type == 'image'" class="o_viewer_toolbar btn-toolbar" role="toolbar">
                 <div class="btn-group ml0" role="group">
                     <a href="#" class="o_viewer_toolbar_btn btn o_zoom_in" data-toggle="tooltip" title="Zoom In"><i class="fa fa-fw fa-plus"/></a>
-                    <a href="#" class="o_viewer_toolbar_btn btn o_zoom_out" data-toggle="tooltip" title="Zoom Out"><i class="fa fa-fw fa-minus"/></a>
+                    <a href="#" class="o_viewer_toolbar_btn btn o_zoom_reset disabled" data-toggle="tooltip" title="Reset Zoom"><i class="fa fa-fw fa-search"/></a>
+                    <a href="#" class="o_viewer_toolbar_btn btn o_zoom_out disabled" data-toggle="tooltip" title="Zoom Out"><i class="fa fa-fw fa-minus"/></a>
                 </div>
-                <div class="btn-group" role="group">
+                <div class="btn-group ml8" role="group">
                     <a href="#" class="o_viewer_toolbar_btn btn o_rotate" data-toggle="tooltip" title="Rotate"><i class="fa fa-fw fa-repeat"/></a>
                 </div>
-                <div class="btn-group" role="group">
+                <div class="btn-group ml8" role="group">
                     <a href="#" class="o_viewer_toolbar_btn btn o_print_btn" data-toggle="tooltip" title="Print"><i class="fa fa-fw fa-print"/></a>
                     <a href="#" class="o_viewer_toolbar_btn btn o_download_btn" data-toggle="tooltip" title="Download"><i class="fa fa-fw fa-download"/></a>
                 </div>