diff --git a/api/src/Mailer.php b/api/src/Mailer.php
index 711dff869f..7b69cb5813 100644
--- a/api/src/Mailer.php
+++ b/api/src/Mailer.php
@@ -75,7 +75,7 @@ class Mailer extends Horde_Mime_Mail
 
 		if ($account !== false)
 		{
-			$this->_headers->setUserAgent('EGroupware API '.$GLOBALS['egw_info']['server']['versions']['phpgwapi']);
+			$this->_headers->setUserAgent('EGroupware API '.$GLOBALS['egw_info']['server']['versions']['api']);
 
 			$this->setAccount($account);
 
@@ -596,7 +596,7 @@ class Mailer extends Horde_Mime_Mail
 		if ($GLOBALS['egw_info']['server']['log_mail'])
 		{
 			$msg = $GLOBALS['egw_info']['server']['log_mail'] !== true ? date('Y-m-d H:i:s')."\n" : '';
-			$msg .= (isset($e) ? 'Mail send' : 'Mail NOT send').
+			$msg .= (!isset($e) ? 'Mail send' : 'Mail NOT send').
 				' to '.implode(', ', $to).' with subject: "'.$subject.'"';
 
 			$msg .= ' from instance '.$GLOBALS['egw_info']['user']['domain'].' and IP '.Session::getuser_ip();
diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index 1dadfd809e..e42da056aa 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -828,7 +828,6 @@ class calendar_boupdate extends calendar_bo
 		$event = $msg_type == MSG_ADDED || $msg_type == MSG_MODIFIED ? $new_event : $old_event;
 
 		// add all group-members to the notification, unless they are already participants
-		$contact_obj = false;
 		foreach($to_notify as $userid => $statusid)
 		{
 			if (is_numeric($userid) && $GLOBALS['egw']->accounts->get_type($userid) == 'g' &&
@@ -1047,6 +1046,10 @@ class calendar_boupdate extends calendar_bo
 
 						if(is_array($attachment)) { $notification->set_attachments(array($attachment)); }
 						$notification->send();
+						foreach(notifications::errors(true) as $error)
+						{
+							error_log(__METHOD__."() Error notifying $userid from $senderid: $subject: $error");
+						}
 					}
 					catch (Exception $exception) {
 						error_log(__METHOD__.' error while notifying user '.$userid.':'.$exception->getMessage());