diff --git a/src/js/bo/outbox.js b/src/js/bo/outbox.js
index 648986e..35dca95 100644
--- a/src/js/bo/outbox.js
+++ b/src/js/bo/outbox.js
@@ -65,6 +65,16 @@ define(function(require) {
         delete this._intervalId;
     };
 
+    /**
+     * Private Api which is called whenever a message has been sent
+     * The public callback "onSent" can be set by the caller to get notified.
+     */
+    OutboxBO.prototype._onSent = function(message) {
+        if (typeof this.onSent === 'function') {
+            this.onSent(message);
+        }
+    };
+
     /**
      * Checks the local device storage for pending mails.
      * @param {Function} callback(error, pendingMailsCount) Callback that informs you about the count of pending mails.
@@ -225,6 +235,10 @@ define(function(require) {
                         callback(err);
                         return;
                     }
+
+                    // fire sent notification
+                    self._onSent(invitationMail);
+
                     invitationFinished();
                 });
             }
@@ -241,6 +255,9 @@ define(function(require) {
                     return;
                 }
 
+                // fire sent notification
+                self._onSent(email);
+
                 removeFromStorage(email.id);
             });
         }
diff --git a/src/js/controller/mail-list.js b/src/js/controller/mail-list.js
index 3bc9c96..66bee59 100644
--- a/src/js/controller/mail-list.js
+++ b/src/js/controller/mail-list.js
@@ -79,6 +79,11 @@ define(function(require) {
             emailDao.sync({
                 folder: getFolder().path
             }, function(err) {
+                if (err && err.code === 409) {
+                    // sync still busy
+                    return;
+                }
+
                 if (err) {
                     updateStatus('Error on sync!');
                     $scope.onError(err);
@@ -176,10 +181,10 @@ define(function(require) {
         //
 
         function notificationForEmail(email) {
-            chrome.notifications.create('' + email.uid, {
+            chrome.notifications.create('i' + email.uid, {
                 type: 'basic',
-                title: email.from[0].address,
-                message: email.subject.split(str.subjectPrefix)[1],
+                title: email.from[0].name || email.from[0].address,
+                message: email.subject.replace(str.subjectPrefix, ''),
                 iconUrl: chrome.runtime.getURL(cfg.iconPath)
             }, function() {});
         }
diff --git a/src/js/controller/navigation.js b/src/js/controller/navigation.js
index 9f08a96..429f542 100644
--- a/src/js/controller/navigation.js
+++ b/src/js/controller/navigation.js
@@ -2,6 +2,8 @@ define(function(require) {
     'use strict';
 
     var angular = require('angular'),
+        str = require('js/app-config').string,
+        cfg = require('js/app-config').config,
         appController = require('js/app-controller'),
         errorUtil = require('js/util/error'),
         _ = require('underscore'),
@@ -67,6 +69,8 @@ define(function(require) {
                 // get pointer to account/folder/message tree on root scope
                 $scope.$root.account = emailDao._account;
 
+                // set notificatio handler for sent messages
+                outboxBo.onSent = sentNotification;
                 // start checking outbox periodically
                 outboxBo.startChecking($scope.onOutboxUpdate);
                 // make function available globally for write controller
@@ -98,6 +102,15 @@ define(function(require) {
                 path: 'TRASH'
             }];
         }
+
+        function sentNotification(email) {
+            chrome.notifications.create('o' + email.id, {
+                type: 'basic',
+                title: 'Sent successfully!',
+                message: email.subject.replace(str.subjectPrefix, ''),
+                iconUrl: chrome.runtime.getURL(cfg.iconPath)
+            }, function() {});
+        }
     };
 
     //
diff --git a/src/js/dao/email-dao.js b/src/js/dao/email-dao.js
index 3d39c8c..9751f29 100644
--- a/src/js/dao/email-dao.js
+++ b/src/js/dao/email-dao.js
@@ -165,7 +165,8 @@ define(function(require) {
 
         if (self._account.busy) {
             callback({
-                errMsg: 'Sync aborted: Previous sync still in progress'
+                errMsg: 'Sync aborted: Previous sync still in progress',
+                code: 409
             });
             return;
         }