diff --git a/NEWS b/NEWS
index 5288e6534..037720bfa 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,7 @@ Bug fixes
  - [web] restored Catalan and Slovak translations (#3687)
  - [web] fixed restore of mailboxes expansion state when multiple IMAP accounts are configured
  - [web] improved CSS sanitizer for HTML messages (#3700)
+ - [web] fixed toolbar of mail editor when sender address was too long (#3705)
  - [core] strip X- tags when securing content (#3695)
 
 3.1.0 (2016-05-18)
diff --git a/UI/Templates/MailerUI/UIxMailEditor.wox b/UI/Templates/MailerUI/UIxMailEditor.wox
index 1d340c86d..fcf1f4c19 100644
--- a/UI/Templates/MailerUI/UIxMailEditor.wox
+++ b/UI/Templates/MailerUI/UIxMailEditor.wox
@@ -10,219 +10,222 @@
              nv-file-over="nv-file-over"
              over-class="sg-over-dropzone"
              uploader="editor.uploader">
-    <md-toolbar>
-      <div class="md-toolbar-tools">
-        <md-icon class="sg-icon-toolbar-bg">edit</md-icon>
-        <!-- from -->
-        <sg-avatar-image hide-sm="hide-sm"
-                         sg-email="editor.message.editable.from"
-                         size="32"><!-- avatar --></sg-avatar-image>
-        <md-input-container flex="flex">
-          <label><var:string label:value="From"/></label>
-          <md-select class="sg-no-wrap" name="from"
-                     ng-model="editor.message.editable.from">
-            <md-option ng-value="identity" ng-repeat="identity in editor.identities">{{identity}}</md-option>
-          </md-select>
-        </md-input-container>
-        <div flex-gt-sm="flex-gt-sm"><!-- spacer --></div>
-        <md-button class="sg-icon-button" ng-click="editor.send()"
-                   ng-disabled="!(editor.message.editable.to.length > 0 || editor.message.editable.cc.length > 0 || editor.message.editable.bcc.length > 0)">
-          <md-icon>send</md-icon>
-        </md-button>
-        <md-button class="sg-icon-button" ng-click="editor.save()">
-          <md-icon>save</md-icon>
-        </md-button>
-        <md-button class="sg-icon-button" ng-click="editor.cancel()">
-          <md-icon>close</md-icon>
-        </md-button>
-      </div>
-    </md-toolbar>
-
-    <div class="sg-dropzone">
-      <div layout="column" layout-align="center center" layout-fill="layout-fill">
-        <md-icon>file_upload</md-icon>
-      </div>
-    </div>
-
-    <md-dialog-content>
-      <header class="sg-padded">
-        <div class="msg-header-content">
-
-          <!-- to -->
-          <div class="pseudo-input-container">
-            <label class="pseudo-input-label">
-              <var:string label:value="To"/>
-            </label>
-            <md-chips ng-model="editor.message.editable.to"
-                      md-separator-keys="editor.recipientSeparatorKeys"
-                      md-transform-chip="editor.addRecipient($chip, 'to')"
-                      sg-transform-on-blur="sg-transform-on-blur">
-              <md-autocomplete
-                  class="sg-chips-autocomplete"
-                  md-autofocus="true"
-                  md-search-text="editor.autocomplete.to.searchText"
-                  md-selected-item="editor.autocomplete.to.selected"
-                  md-items="user in editor.contactFilter(editor.autocomplete.to.searchText)"
-                  md-min-length="3"
-                  md-delay="150"
-                  md-no-cache="true"
-                  label:placeholder="Add a recipient">
-                <md-item-template>
-                  <span class="md-contact-suggestion">
-                    <span class="md-contact-name"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$fullname}}</span>
-                    <span class="md-contact-email"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$email}}</span>
-                  </span>
-                </md-item-template>
-              </md-autocomplete>
-              <md-chip-template>{{$chip}}</md-chip-template>
-            </md-chips>
-          </div>
-
-          <!-- cc -->
-          <div class="pseudo-input-container ng-hide" ng-hide="editor.hideCc">
-            <label class="pseudo-input-label">
-              <var:string label:value="Cc"/>
-            </label>
-            <md-chips ng-model="editor.message.editable.cc"
-                      md-separator-keys="editor.recipientSeparatorKeys"
-                      md-transform-chip="editor.addRecipient($chip, 'cc')"
-                      sg-transform-on-blur="sg-transform-on-blur">
-              <md-autocomplete
-                  class="sg-chips-autocomplete"
-                  md-search-text="editor.autocomplete.cc.searchText"
-                  md-selected-item="editor.autocomplete.cc.selected"
-                  md-items="user in editor.contactFilter(editor.autocomplete.cc.searchText)"
-                  md-min-length="3"
-                  md-delay="300"
-                  md-no-cache="true"
-                  label:placeholder="Add a recipient">
-                <md-item-template>
-                  <span class="md-contact-suggestion">
-                    <span class="md-contact-name"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$fullname}}</span>
-                    <span class="md-contact-email"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$email}}</span>
-                  </span>
-                </md-item-template>
-              </md-autocomplete>
-              <md-chip-template>{{$chip}}</md-chip-template>
-            </md-chips>
-          </div>
-
-          <!-- bcc -->
-          <div class="pseudo-input-container ng-hide" ng-hide="editor.hideBcc">
-            <label class="pseudo-input-label">
-              <var:string label:value="Bcc"/>
-            </label>
-            <md-chips ng-model="editor.message.editable.bcc"
-                      md-separator-keys="editor.recipientSeparatorKeys"
-                      md-transform-chip="editor.addRecipient($chip, 'bcc')"
-                      sg-transform-on-blur="sg-transform-on-blur">
-              <md-autocomplete
-                  class="sg-chips-autocomplete"
-                  md-selected-item="editor.autocomplete.bcc.selected"
-                  md-search-text="editor.autocomplete.bcc.searchText"
-                  md-items="user in editor.contactFilter(editor.autocomplete.bcc.searchText)"
-                  md-min-length="3"
-                  md-delay="300"
-                  md-no-cache="true"
-                  label:placeholder="Add a recipient">
-                <md-item-template>
-                  <span class="md-contact-suggestion">
-                    <span class="md-contact-name"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$fullname}}</span>
-                    <span class="md-contact-email"
-                          md-highlight-text="editor.autocomplete.to.searchText"
-                          md-highlight-flags="^i">{{user.$$email}}</span>
-                  </span>
-                </md-item-template>
-              </md-autocomplete>
-              <md-chip-template>{{$chip}}</md-chip-template>
-            </md-chips>
-          </div>
-
-          <!-- subject -->
-          <md-input-container>
-            <label>
-              <var:string label:value="Subject"/>
-            </label>
-            <input type="text" name="subject" ng-model="editor.message.editable.subject"/>
+    <form name="messageForm">
+      <md-toolbar>
+        <div class="md-toolbar-tools">
+          <!-- from -->
+          <sg-avatar-image class="hide-xs"
+                           sg-email="editor.message.editable.from"
+                           size="32"><!-- avatar --></sg-avatar-image>
+          <md-input-container class="sg-no-wrap">
+            <label><var:string label:value="From"/></label>
+            <md-select name="from"
+                       ng-model="editor.message.editable.from">
+              <md-option ng-value="identity" ng-repeat="identity in editor.identities">{{identity}}</md-option>
+            </md-select>
           </md-input-container>
+          <div flex="flex"><!-- spacer --></div>
+          <md-button class="sg-icon-button" ng-click="editor.send()"
+                     ng-disabled="!(editor.message.editable.to.length > 0 || editor.message.editable.cc.length > 0 || editor.message.editable.bcc.length > 0) || messageForm.$invalid">
+            <md-icon>send</md-icon>
+          </md-button>
+          <md-button class="sg-icon-button" ng-click="editor.save()">
+            <md-icon>save</md-icon>
+          </md-button>
+          <md-button class="sg-icon-button" ng-click="editor.cancel()">
+            <md-icon>close</md-icon>
+          </md-button>
         </div>
+      </md-toolbar>
 
-        <!-- toolbar to show cc/bcc/attachment fields -->
-        <div layout="column" layout-align="start end">
-          <md-button class="sg-icon-button " ng-show="editor.hideCc" ng-click="editor.hideCc = false">Cc</md-button>
-          <md-button class="sg-icon-button " ng-show="editor.hideBcc" ng-click="editor.hideBcc = false">Bcc</md-button>
-          <md-menu>
-            <md-button label:aria-label="More mail options" class="sg-icon-button" ng-click="$mdOpenMenu($event)">
-              <md-icon>more_vert</md-icon>
-            </md-button>
-            <md-menu-content width="4">
-              <md-menu-item>
-                <sg-checkmark ng-model="editor.message.editable.receipt">
-                  <var:string label:value="Return Receipt"/>
-                </sg-checkmark>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button class="md-primary" ng-disabled="true"><var:string label:value="Priority"/></md-button>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button ng-click="editor.message.editable.priority = 1">
-                  <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 1}"><!-- highest --></md-icon>
-                  <var:string label:value="highest"/>
-                </md-button>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button ng-click="editor.message.editable.priority = 2">
-                  <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 2}"><!-- high --></md-icon>
-                  <var:string label:value="high"/>
-                </md-button>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button ng-click="editor.message.editable.priority = 3">
-                  <md-icon ng-class="{ 'icon-check':
-                                     !editor.message.editable.priority
-                                     || editor.message.editable.priority == 3}"><!-- normal --></md-icon>
-                  <var:string label:value="normal"/>
-                </md-button>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button ng-click="editor.message.editable.priority = 4">
-                  <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 4}"><!-- low --></md-icon>
-                  <var:string label:value="low"/>
-                </md-button>
-              </md-menu-item>
-              <md-menu-item>
-                <md-button ng-click="editor.message.editable.priority = 5">
-                  <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 5}"><!-- lowest --></md-icon>
-                  <var:string label:value="lowest"/>
-                </md-button>
-              </md-menu-item>
-            </md-menu-content>
-          </md-menu>
-
+      <div class="sg-dropzone">
+        <div layout="column" layout-align="center center" layout-fill="layout-fill">
+          <md-icon>file_upload</md-icon>
         </div>
-      </header>
-
-      <!-- MESSAGE CONTENT -->
-      <div var:class="editorClass">
-        <textarea name="content" var:class="editorClass"
-                  ck-locale="editor.localeCode"
-                  ng-model="editor.message.editable.text"/>
       </div>
-    </md-dialog-content>
 
-    <!-- ATTACHMENTS -->
-    <md-dialog-actions>
-      <div layout="row" layout-align="space-between center" layout-fill="layout-fill">
+      <md-dialog-content>
+        <header class="sg-padded">
+          <div class="msg-header-content">
+
+            <!-- to -->
+            <div class="pseudo-input-container">
+              <label class="pseudo-input-label">
+                <var:string label:value="To"/>
+              </label>
+              <md-chips ng-model="editor.message.editable.to"
+                        md-separator-keys="editor.recipientSeparatorKeys"
+                        md-transform-chip="editor.addRecipient($chip, 'to')"
+                        sg-transform-on-blur="sg-transform-on-blur">
+                <md-autocomplete
+                    class="sg-chips-autocomplete"
+                    md-autofocus="true"
+                    md-search-text="editor.autocomplete.to.searchText"
+                    md-selected-item="editor.autocomplete.to.selected"
+                    md-items="user in editor.contactFilter(editor.autocomplete.to.searchText)"
+                    md-min-length="3"
+                    md-delay="150"
+                    md-no-cache="true"
+                    label:placeholder="Add a recipient">
+                  <md-item-template>
+                    <span class="md-contact-suggestion">
+                      <span class="md-contact-name"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$fullname}}</span>
+                      <span class="md-contact-email"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$email}}</span>
+                    </span>
+                  </md-item-template>
+                </md-autocomplete>
+                <md-chip-template>{{$chip}}</md-chip-template>
+              </md-chips>
+            </div>
+
+            <!-- cc -->
+            <div class="pseudo-input-container ng-hide" ng-hide="editor.hideCc">
+              <label class="pseudo-input-label">
+                <var:string label:value="Cc"/>
+              </label>
+              <md-chips ng-model="editor.message.editable.cc"
+                        md-separator-keys="editor.recipientSeparatorKeys"
+                        md-transform-chip="editor.addRecipient($chip, 'cc')"
+                        sg-transform-on-blur="sg-transform-on-blur">
+                <md-autocomplete
+                    class="sg-chips-autocomplete"
+                    md-search-text="editor.autocomplete.cc.searchText"
+                    md-selected-item="editor.autocomplete.cc.selected"
+                    md-items="user in editor.contactFilter(editor.autocomplete.cc.searchText)"
+                    md-min-length="3"
+                    md-delay="300"
+                    md-no-cache="true"
+                    label:placeholder="Add a recipient">
+                  <md-item-template>
+                    <span class="md-contact-suggestion">
+                      <span class="md-contact-name"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$fullname}}</span>
+                      <span class="md-contact-email"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$email}}</span>
+                    </span>
+                  </md-item-template>
+                </md-autocomplete>
+                <md-chip-template>{{$chip}}</md-chip-template>
+              </md-chips>
+            </div>
+
+            <!-- bcc -->
+            <div class="pseudo-input-container ng-hide" ng-hide="editor.hideBcc">
+              <label class="pseudo-input-label">
+                <var:string label:value="Bcc"/>
+              </label>
+              <md-chips ng-model="editor.message.editable.bcc"
+                        md-separator-keys="editor.recipientSeparatorKeys"
+                        md-transform-chip="editor.addRecipient($chip, 'bcc')"
+                        sg-transform-on-blur="sg-transform-on-blur">
+                <md-autocomplete
+                    class="sg-chips-autocomplete"
+                    md-selected-item="editor.autocomplete.bcc.selected"
+                    md-search-text="editor.autocomplete.bcc.searchText"
+                    md-items="user in editor.contactFilter(editor.autocomplete.bcc.searchText)"
+                    md-min-length="3"
+                    md-delay="300"
+                    md-no-cache="true"
+                    label:placeholder="Add a recipient">
+                  <md-item-template>
+                    <span class="md-contact-suggestion">
+                      <span class="md-contact-name"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$fullname}}</span>
+                      <span class="md-contact-email"
+                            md-highlight-text="editor.autocomplete.to.searchText"
+                            md-highlight-flags="^i">{{user.$$email}}</span>
+                    </span>
+                  </md-item-template>
+                </md-autocomplete>
+                <md-chip-template>{{$chip}}</md-chip-template>
+              </md-chips>
+            </div>
+
+            <!-- subject -->
+            <md-input-container>
+              <label>
+                <var:string label:value="Subject"/>
+              </label>
+              <input type="text" name="subject" ng-model="editor.message.editable.subject" ng-required="true"/>
+              <div ng-messages="messageForm.subject.$error">
+                <div ng-message="required"><var:string label:value="error_missingsubject"/></div>
+              </div>
+            </md-input-container>
+          </div>
+
+          <!-- toolbar to show cc/bcc/attachment fields -->
+          <div layout="column" layout-align="start end">
+            <md-button class="sg-icon-button " ng-show="editor.hideCc" ng-click="editor.hideCc = false">Cc</md-button>
+            <md-button class="sg-icon-button " ng-show="editor.hideBcc" ng-click="editor.hideBcc = false">Bcc</md-button>
+            <md-menu>
+              <md-button label:aria-label="More mail options" class="sg-icon-button" ng-click="$mdOpenMenu($event)">
+                <md-icon>more_vert</md-icon>
+              </md-button>
+              <md-menu-content width="4">
+                <md-menu-item>
+                  <sg-checkmark ng-model="editor.message.editable.receipt">
+                    <var:string label:value="Return Receipt"/>
+                  </sg-checkmark>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button class="md-primary" ng-disabled="true"><var:string label:value="Priority"/></md-button>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button ng-click="editor.message.editable.priority = 1">
+                    <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 1}"><!-- highest --></md-icon>
+                    <var:string label:value="highest"/>
+                  </md-button>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button ng-click="editor.message.editable.priority = 2">
+                    <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 2}"><!-- high --></md-icon>
+                    <var:string label:value="high"/>
+                  </md-button>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button ng-click="editor.message.editable.priority = 3">
+                    <md-icon ng-class="{ 'icon-check':
+                                       !editor.message.editable.priority
+                                       || editor.message.editable.priority == 3}"><!-- normal --></md-icon>
+                    <var:string label:value="normal"/>
+                  </md-button>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button ng-click="editor.message.editable.priority = 4">
+                    <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 4}"><!-- low --></md-icon>
+                    <var:string label:value="low"/>
+                  </md-button>
+                </md-menu-item>
+                <md-menu-item>
+                  <md-button ng-click="editor.message.editable.priority = 5">
+                    <md-icon ng-class="{ 'icon-check': editor.message.editable.priority == 5}"><!-- lowest --></md-icon>
+                    <var:string label:value="lowest"/>
+                  </md-button>
+                </md-menu-item>
+              </md-menu-content>
+            </md-menu>
+
+          </div>
+        </header>
+
+        <!-- MESSAGE CONTENT -->
+        <div var:class="editorClass">
+          <textarea name="content" var:class="editorClass"
+                    ck-locale="editor.localeCode"
+                    ng-model="editor.message.editable.text"/>
+        </div>
+      </md-dialog-content>
+
+      <!-- ATTACHMENTS -->
+      <md-dialog-actions>
+        <div layout="row" layout-align="space-between center" layout-fill="layout-fill">
           <!-- Attachments -->
           <md-chips ng-model="editor.uploader.queue"
                     class="md-flex sg-readonly" readonly="true">
@@ -247,8 +250,9 @@
               Disable multiple until this issue is resolved:
               https://github.com/nervgh/angular-file-upload/issues/525
           -->
-                 <!-- multiple="multiple" -->
-      </div>
-    </md-dialog-actions>
+          <!-- multiple="multiple" -->
+        </div>
+      </md-dialog-actions>
+    </form>
   </md-dialog>
 </container>