diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
index a640c651..b5504182 100644
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -1,304 +1,304 @@
 <?php
 
 /**
  * Localizations for Kolab Calendar plugin
  *
  * Copyright (C) 2014, Kolab Systems AG
  *
  * For translation see https://www.transifex.com/projects/p/kolab/resource/calendar/
  */
 
 $labels = array();
 
 // preferences
 $labels['default_view'] = 'Default view';
 $labels['time_format'] = 'Time format';
 $labels['timeslots'] = 'Time slots per hour';
 $labels['first_day'] = 'First weekday';
 $labels['first_hour'] = 'First hour to show';
 $labels['workinghours'] = 'Working hours';
 $labels['add_category'] = 'Add category';
 $labels['remove_category'] = 'Remove category';
 $labels['defaultcalendar'] = 'Create new events in';
 $labels['eventcoloring'] = 'Event coloring';
 $labels['coloringmode0'] = 'According to calendar';
 $labels['coloringmode1'] = 'According to category';
 $labels['coloringmode2'] = 'Calendar for outline, category for content';
 $labels['coloringmode3'] = 'Category for outline, calendar for content';
 $labels['afternothing'] = 'Do nothing';
 $labels['aftertrash'] = 'Move to Trash';
 $labels['afterdelete'] = 'Delete the message';
 $labels['afterflagdeleted'] = 'Flag as deleted';
 $labels['aftermoveto'] = 'Move to...';
 $labels['itipoptions'] = 'Event Invitations';
 $labels['afteraction'] = 'After an invitation or update message is processed';
 
 // calendar
 $labels['calendar'] = 'Calendar';
 $labels['calendars'] = 'Calendars';
 $labels['category'] = 'Category';
 $labels['categories'] = 'Categories';
 $labels['createcalendar'] = 'Create new calendar';
 $labels['editcalendar'] = 'Edit calendar properties';
 $labels['name'] = 'Name';
 $labels['color'] = 'Color';
 $labels['day'] = 'Day';
 $labels['week'] = 'Week';
 $labels['month'] = 'Month';
 $labels['agenda'] = 'Agenda';
 $labels['new'] = 'New';
 $labels['new_event'] = 'New event';
 $labels['edit_event'] = 'Edit event';
 $labels['edit'] = 'Edit';
 $labels['save'] = 'Save';
 $labels['removelist'] = 'Remove from list';
 $labels['cancel'] = 'Cancel';
 $labels['select'] = 'Select';
 $labels['print'] = 'Print';
 $labels['printtitle'] = 'Print calendars';
 $labels['title'] = 'Summary';
 $labels['description'] = 'Description';
 $labels['all-day'] = 'all-day';
 $labels['export'] = 'Export';
 $labels['exporttitle'] = 'Export to iCalendar';
 $labels['exportrange'] = 'Events from';
 $labels['exportattachments'] = 'With attachments';
 $labels['customdate'] = 'Custom date';
 $labels['location'] = 'Location';
 $labels['url'] = 'URL';
 $labels['date'] = 'Date';
 $labels['start'] = 'Start';
 $labels['starttime'] = 'Start time';
 $labels['end'] = 'End';
 $labels['endtime'] = 'End time';
 $labels['repeat'] = 'Repeat';
 $labels['selectdate'] = 'Choose date';
 $labels['freebusy'] = 'Show me as';
 $labels['free'] = 'Free';
 $labels['busy'] = 'Busy';
 $labels['outofoffice'] = 'Out of Office';
 $labels['tentative'] = 'Tentative';
 $labels['mystatus'] = 'My status';
 $labels['status'] = 'Status';
 $labels['status-confirmed'] = 'Confirmed';
 $labels['status-cancelled'] = 'Cancelled';
 $labels['status-tentative'] = 'Tentative';
 $labels['priority'] = 'Priority';
 $labels['sensitivity'] = 'Privacy';
 $labels['public'] = 'public';
 $labels['private'] = 'private';
 $labels['confidential'] = 'confidential';
 $labels['links'] = 'Reference';
 $labels['alarms'] = 'Reminder';
 $labels['comment'] = 'Comment';
 $labels['created'] = 'Created';
 $labels['changed'] = 'Last Modified';
 $labels['unknown'] = 'Unknown';
 $labels['eventoptions'] = 'Options';
 $labels['generated'] = 'generated at';
 $labels['eventhistory'] = 'History';
 $labels['removelink'] = 'Remove email reference';
 $labels['printdescriptions'] = 'Print descriptions';
 $labels['parentcalendar'] = 'Insert inside';
 $labels['searchearlierdates'] = '« Search for earlier events';
 $labels['searchlaterdates'] = 'Search for later events »';
 $labels['andnmore'] = '$nr more...';
 $labels['togglerole'] = 'Click to toggle role';
 $labels['createfrommail'] = 'Save as event';
 $labels['importevents'] = 'Import events';
 $labels['importrange'] = 'Events from';
 $labels['onemonthback'] = '1 month back';
 $labels['nmonthsback'] = '$nr months back';
 $labels['showurl'] = 'Show calendar URL';
 $labels['showurldescription'] = 'Use the following address to access (read only) your calendar from other applications. You can copy and paste this into any calendar software that supports the iCal format.';
 $labels['caldavurldescription'] = 'Copy this address to a <a href="http://en.wikipedia.org/wiki/CalDAV" target="_blank">CalDAV</a> client application (e.g. Evolution or Mozilla Thunderbird) to fully synchronize this specific calendar with your computer or mobile device.';
 $labels['showfburl'] = 'Show free-busy URL';
 $labels['fburldescription'] = 'Use the following address to access Free-Busy information from other applications. You can copy and paste this into any calendar software that supports free-busy information in iCal format. No authentication is required for this URL.';
 $labels['findcalendars'] = 'Find calendars...';
 $labels['searchterms'] = 'Search terms';
 $labels['calsearchresults'] = 'Available Calendars';
 $labels['calendarsubscribe'] = 'List permanently';
 $labels['nocalendarsfound'] = 'No calendars found';
 $labels['nrcalendarsfound'] = '$nr calendars found';
 $labels['quickview'] = 'View only this calendar';
 $labels['invitationspending'] = 'Pending invitations';
 $labels['invitationsdeclined'] = 'Declined invitations';
 $labels['changepartstat'] = 'Change participant status';
 $labels['rsvpcomment'] = 'Invitation text';
 $labels['eventstartsync'] = 'Move the event start date to the first occurrence';
 
 // agenda view
 $labels['listrange'] = 'Range to display:';
 $labels['listsections'] = 'Divide into:';
 $labels['smartsections'] = 'Smart sections';
 $labels['until'] = 'until';
 $labels['today'] = 'Today';
 $labels['tomorrow'] = 'Tomorrow';
 $labels['thisweek'] = 'This week';
 $labels['nextweek'] = 'Next week';
 $labels['prevweek'] = 'Previous week';
 $labels['thismonth'] = 'This month';
 $labels['nextmonth'] = 'Next month';
 $labels['weekofyear'] = 'Week';
 $labels['pastevents'] = 'Past';
 $labels['futureevents'] = 'Future';
 
 // alarm/reminder settings
 $labels['showalarms'] = 'Show reminders';
 $labels['defaultalarmtype'] = 'Default reminder setting';
 $labels['defaultalarmoffset'] = 'Default reminder time';
 
 // attendees
 $labels['attendee'] = 'Participant';
 $labels['role'] = 'Role';
 $labels['availability'] = 'Avail.';
 $labels['confirmstate'] = 'Status';
 $labels['addattendee'] = 'Add participant';
 $labels['roleorganizer'] = 'Organizer';
 $labels['rolerequired'] = 'Required';
 $labels['roleoptional'] = 'Optional';
 $labels['rolechair'] = 'Chair';
 $labels['rolenonparticipant'] = 'Absent';
 $labels['cutypeindividual'] = 'Individual';
 $labels['cutypegroup'] = 'Group';
 $labels['cutyperesource'] = 'Resource';
 $labels['cutyperoom'] = 'Room';
 $labels['availfree'] = 'Free';
 $labels['availbusy'] = 'Busy';
 $labels['availunknown'] = 'Unknown';
 $labels['availtentative'] = 'Tentative';
 $labels['availoutofoffice'] = 'Out of Office';
 $labels['scheduletime'] = 'Find availability';
 $labels['sendinvitations'] = 'Send invitations';
 $labels['sendnotifications'] = 'Notify participants about modifications';
 $labels['sendcancellation'] = 'Notify participants about event cancellation';
 $labels['onlyworkinghours'] = 'Find availability within my working hours';
 $labels['reqallattendees'] = 'Required/all participants';
 $labels['prevslot'] = 'Previous Slot';
 $labels['nextslot'] = 'Next Slot';
 $labels['suggestedslot'] = 'Suggested Slot';
 $labels['noslotfound'] = 'Unable to find a free time slot';
 $labels['invitationsubject'] = 'You\'ve been invited to "$title"';
-$labels['invitationmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nPlease find attached an iCalendar file with all the event details which you can import to your calendar application.";
+$labels['invitationmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\n\$description\n\nPlease find attached an iCalendar file with all the event details which you can import to your calendar application.";
 $labels['invitationattendlinks'] = "In case your email client doesn't support iTip requests you can use the following link to either accept or decline this invitation:\n\$url";
 $labels['eventupdatesubject'] = '"$title" has been updated';
 $labels['eventupdatesubjectempty'] = 'An event that concerns you has been updated';
 $labels['eventupdatemailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nPlease find attached an iCalendar file with the updated event details which you can import to your calendar application.";
 $labels['eventcancelsubject'] = '"$title" has been cancelled';
 $labels['eventcancelmailbody'] = "*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees\n\nThe event has been cancelled by \$organizer.\n\nPlease find attached an iCalendar file with the updated event details.";
 
 // invitation handling (overrides labels from libcalendaring)
 $labels['itipobjectnotfound'] = 'The event referred by this message was not found in your calendar.';
 
 $labels['itipmailbodyaccepted'] = "\$sender has accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodytentative'] = "\$sender has tentatively accepted the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodydeclined'] = "\$sender has declined the invitation to the following event:\n\n*\$title*\n\nWhen: \$date\n\nInvitees: \$attendees";
 $labels['itipmailbodycancel'] = "\$sender has rejected your participation in the following event:\n\n*\$title*\n\nWhen: \$date";
 $labels['itipmailbodydelegated'] = "\$sender has delegated the participation in the following event:\n\n*\$title*\n\nWhen: \$date";
 $labels['itipmailbodydelegatedto'] = "\$sender has delegated the participation in the following event to you:\n\n*\$title*\n\nWhen: \$date";
 
 $labels['itipdeclineevent'] = 'Do you want to decline your invitation to this event?';
 $labels['declinedeleteconfirm'] = 'Do you also want to delete this declined event from your calendar?';
 $labels['itipcomment'] = 'Invitation/notification comment';
 $labels['itipcommenttitle'] = 'This comment will be attached to the invitation/notification message sent to participants';
 
 $labels['notanattendee'] = 'You\'re not listed as an attendee of this event';
 $labels['eventcancelled'] = 'The event has been cancelled';
 $labels['saveincalendar'] = 'save in';
 $labels['updatemycopy'] = 'Update in my calendar';
 $labels['savetocalendar'] = 'Save to calendar';
 $labels['openpreview'] = 'Check Calendar';
 $labels['noearlierevents'] = 'No earlier events';
 $labels['nolaterevents'] = 'No later events';
 
 // resources
 $labels['resource'] = 'Resource';
 $labels['addresource'] = 'Book resource';
 $labels['findresources'] = 'Find resources';
 $labels['resourcedetails'] = 'Details';
 $labels['resourceavailability'] = 'Availability';
 $labels['resourceowner'] = 'Owner';
 $labels['resourceadded'] = 'The resource was added to your event';
 
 // event dialog tabs
 $labels['tabsummary'] = 'Summary';
 $labels['tabrecurrence'] = 'Recurrence';
 $labels['tabattendees'] = 'Participants';
 $labels['tabresources'] = 'Resources';
 $labels['tabattachments'] = 'Attachments';
 $labels['tabsharing'] = 'Sharing';
 
 // messages
 $labels['deleteobjectconfirm'] = 'Do you really want to delete this event?';
 $labels['deleteventconfirm'] = 'Do you really want to delete this event?';
 $labels['deletecalendarconfirm'] = 'Do you really want to delete this calendar with all its events?';
 $labels['deletecalendarconfirmrecursive'] = 'Do you really want to delete this calendar with all its events and sub-calendars?';
 $labels['savingdata'] = 'Saving data...';
 $labels['errorsaving'] = 'Failed to save changes.';
 $labels['operationfailed'] = 'The requested operation failed.';
 $labels['invalideventdates'] = 'Invalid dates entered! Please check your input.';
 $labels['invalidcalendarproperties'] = 'Invalid calendar properties! Please set a valid name.';
 $labels['searchnoresults'] = 'No events found in the selected calendars.';
 $labels['successremoval'] = 'The event has been deleted successfully.';
 $labels['successrestore'] = 'The event has been restored successfully.';
 $labels['errornotifying'] = 'Failed to send notifications to event participants';
 $labels['errorimportingevent'] = 'Failed to import the event';
 $labels['importwarningexists'] = 'A copy of this event already exists in your calendar.';
 $labels['newerversionexists'] = 'A newer version of this event already exists! Aborted.';
 $labels['nowritecalendarfound'] = 'No calendar found to save the event';
 $labels['importedsuccessfully'] = 'The event was successfully added to \'$calendar\'';
 $labels['updatedsuccessfully'] = 'The event was successfully updated in \'$calendar\'';
 $labels['attendeupdateesuccess'] = 'Successfully updated the participant\'s status';
 $labels['itipsendsuccess'] = 'Invitation sent to participants.';
 $labels['itipresponseerror'] = 'Failed to send the response to this event invitation';
 $labels['itipinvalidrequest'] = 'This invitation is no longer valid';
 $labels['sentresponseto'] = 'Successfully sent invitation response to $mailto';
 $labels['localchangeswarning'] = 'You are about to make changes that will only be reflected on your calendar and not be sent to the organizer of the event.';
 $labels['importsuccess'] = 'Successfully imported $nr events';
 $labels['importnone'] = 'No events found to be imported';
 $labels['importerror'] = 'An error occured while importing';
 $labels['aclnorights'] = 'You do not have administrator rights on this calendar.';
 
 $labels['changeeventconfirm'] = 'Change event';
 $labels['removeeventconfirm'] = 'Delete event';
 $labels['changerecurringeventwarning'] = 'This is a recurring event. Would you like to edit the current event only, this and all future occurences, all occurences or save it as a new event?';
 $labels['removerecurringeventwarning'] = 'This is a recurring event. Would you like to delete the current event only, this and all future occurences or all occurences of this event?';
 $labels['removerecurringallonly'] = 'This is a recurring event. As a participant, you can only delete the entire event with all occurences.';
 $labels['currentevent'] = 'Current';
 $labels['futurevents'] = 'Future';
 $labels['allevents'] = 'All';
 $labels['saveasnew'] = 'Save as new';
 $labels['recurrenceerror'] = 'Unable to resolve recurrence rule for specified start date.';
 
 // birthdays calendar
 $labels['birthdays'] = 'Birthdays';
 $labels['birthdayscalendar'] = 'Birthdays Calendar';
 $labels['displaybirthdayscalendar'] = 'Display birthdays calendar';
 $labels['birthdayscalendarsources'] = 'From these address books';
 $labels['birthdayeventtitle'] = '$name\'s Birthday';
 $labels['birthdayage'] = 'Age $age';
 
 // history dialog
 $labels['objectchangelog'] = 'Change History';
 $labels['objectdiff'] = 'Changes from $rev1 to $rev2';
 $labels['objectnotfound'] = 'Failed to load event data';
 $labels['objectchangelognotavailable'] = 'Change history is not available for this event';
 $labels['objectdiffnotavailable'] = 'No comparison possible for the selected revisions';
 $labels['revisionrestoreconfirm'] = 'Do you really want to restore revision $rev of this event? This will replace the current event with the old version.';
 $labels['objectrestoresuccess'] = 'Revision $rev successfully restored';
 $labels['objectrestoreerror'] = 'Failed to restore the old revision';
 
 
 // (hidden) titles and labels for accessibility annotations
 $labels['arialabelminical'] = 'Calendar date selection';
 $labels['arialabelcalendarview'] = 'Calendar view';
 $labels['arialabelsearchform'] = 'Event search form';
 $labels['arialabelquicksearchbox'] = 'Event search input';
 $labels['arialabelcalsearchform'] = 'Calendars search form';
 $labels['calendaractions'] = 'Calendar actions';
 $labels['arialabeleventattendees'] = 'Event participants list';
 $labels['arialabeleventresources'] = 'Event resources list';
 $labels['arialabelresourcesearchform'] = 'Resources search form';
 $labels['arialabelresourceselection'] = 'Available resources';
 
 ?>
diff --git a/plugins/libcalendaring/lib/libcalendaring_itip.php b/plugins/libcalendaring/lib/libcalendaring_itip.php
index 1b0788c7..b960e9a4 100644
--- a/plugins/libcalendaring/lib/libcalendaring_itip.php
+++ b/plugins/libcalendaring/lib/libcalendaring_itip.php
@@ -1,932 +1,937 @@
 <?php
 
 /**
  * iTIP functions for the calendar-based Roudncube plugins
  *
  * Class providing functionality to manage iTIP invitations
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2011-2014, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 class libcalendaring_itip
 {
     protected $rc;
     protected $lib;
     protected $plugin;
     protected $sender;
     protected $domain;
     protected $itip_send = false;
     protected $rsvp_actions = array('accepted','tentative','declined','delegated');
     protected $rsvp_status  = array('accepted','tentative','declined','delegated');
 
     function __construct($plugin, $domain = 'libcalendaring')
     {
         $this->plugin = $plugin;
         $this->rc = rcube::get_instance();
         $this->lib = libcalendaring::get_instance();
         $this->domain = $domain;
 
         $hook = $this->rc->plugins->exec_hook('calendar_load_itip',
             array('identity' => $this->rc->user->list_emails(true)));
         $this->sender = $hook['identity'];
 
         $this->plugin->add_hook('message_before_send', array($this, 'before_send_hook'));
         $this->plugin->add_hook('smtp_connect', array($this, 'smtp_connect_hook'));
     }
 
     public function set_sender_email($email)
     {
         if (!empty($email))
             $this->sender['email'] = $email;
     }
 
     public function set_rsvp_actions($actions)
     {
         $this->rsvp_actions = (array)$actions;
         $this->rsvp_status = array_merge($this->rsvp_actions, array('delegated'));
     }
 
     public function set_rsvp_status($status)
     {
         $this->rsvp_status = $status;
     }
 
     /**
      * Wrapper for rcube_plugin::gettext()
      * Checking for a label in different domains
      *
      * @see rcube::gettext()
      */
     public function gettext($p)
     {
         $label = is_array($p) ? $p['name'] : $p;
         $domain = $this->domain;
         if (!$this->rc->text_exists($label, $domain)) {
             $domain = 'libcalendaring';
         }
         return $this->rc->gettext($p, $domain);
     }
 
     /**
      * Send an iTip mail message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param array   Hash array with recipient data (name, email)
      * @param string  Mail subject
      * @param string  Mail body text label
      * @param object  Mail_mime object with message data
      * @param boolean Request RSVP
      * @return boolean True on success, false on failure
      */
     public function send_itip_message($event, $method, $recipient, $subject, $bodytext, $message = null, $rsvp = true)
     {
-        if (!$this->sender['name'])
+        if (!$this->sender['name']) {
             $this->sender['name'] = $this->sender['email'];
+        }
 
         if (!$message) {
             libcalendaring::identify_recurrence_instance($event);
             $message = $this->compose_itip_message($event, $method, $rsvp);
         }
 
         $mailto = rcube_utils::idn_to_ascii($recipient['email']);
 
         $headers = $message->headers();
         $headers['To'] = format_email_recipient($mailto, $recipient['name']);
         $headers['Subject'] = $this->gettext(array(
             'name' => $subject,
             'vars' => array(
                 'title' => $event['title'],
-                'name' => $this->sender['name']
+                'name' => $this->sender['name'],
             )
         ));
 
         // compose a list of all event attendees
         $attendees_list = array();
         foreach ((array)$event['attendees'] as $attendee) {
             $attendees_list[] = ($attendee['name'] && $attendee['email']) ?
                 $attendee['name'] . ' <' . $attendee['email'] . '>' :
                 ($attendee['name'] ? $attendee['name'] : $attendee['email']);
         }
 
         $recurrence_info = '';
         if (!empty($event['recurrence_id'])) {
             $recurrence_info = "\n\n** " . $this->gettext($event['thisandfuture'] ? 'itipmessagefutureoccurrence' : 'itipmessagesingleoccurrence') . ' **';
         }
         else if (!empty($event['recurrence'])) {
             $recurrence_info = sprintf("\n%s: %s", $this->gettext('recurring'), $this->lib->recurrence_text($event['recurrence']));
         }
 
         $mailbody = $this->gettext(array(
             'name' => $bodytext,
             'vars' => array(
-                'title' => $event['title'],
-                'date' => $this->lib->event_date_text($event, true) . $recurrence_info,
-                'attendees' => join(",\n ", $attendees_list),
-                'sender' => $this->sender['name'],
-                'organizer' => $this->sender['name'],
+                'title'       => $event['title'],
+                'date'        => $this->lib->event_date_text($event, true) . $recurrence_info,
+                'attendees'   => join(",\n ", $attendees_list),
+                'sender'      => $this->sender['name'],
+                'organizer'   => $this->sender['name'],
+                'description' => $event['description'],
             )
         ));
 
+        // remove redundant empty lines (e.g. when an event description is empty)
+        $mailbody = preg_replace('/\n{3,}/', "\n\n", $mailbody);
+
         // if (!empty($event['comment'])) {
         //     $mailbody .= "\n\n" . $this->gettext('itipsendercomment') . $event['comment'];
         // }
 
         // append links for direct invitation replies
         if ($method == 'REQUEST' && $rsvp && ($token = $this->store_invitation($event, $recipient['email']))) {
             $mailbody .= "\n\n" . $this->gettext(array(
                 'name' => 'invitationattendlinks',
                 'vars' => array('url' => $this->plugin->get_url(array('action' => 'attend', 't' => $token))),
             ));
         }
         else if ($method == 'CANCEL' && $event['cancelled']) {
             $this->cancel_itip_invitation($event);
         }
 
         $message->headers($headers, true);
         $message->setTXTBody(rcube_mime::format_flowed($mailbody, 79));
 
         if ($this->rc->config->get('libcalendaring_itip_debug', false)) {
             rcube::console('iTip ' . $method, $message->txtHeaders() . "\r\n" . $message->get());
         }
 
         // finally send the message
         $this->itip_send = true;
         $sent = $this->rc->deliver_message($message, $headers['X-Sender'], $mailto, $smtp_error);
         $this->itip_send = false;
 
         return $sent;
     }
 
     /**
      * Plugin hook triggered by rcube::deliver_message() before delivering a message.
      * Here we can set the 'smtp_server' config option to '' in order to use
      * PHP's mail() function for unauthenticated email sending.
      */
     public function before_send_hook($p)
     {
         if ($this->itip_send && !$this->rc->user->ID && $this->rc->config->get('calendar_itip_smtp_server', null) === '') {
             $this->rc->config->set('smtp_server', '');
         }
 
         return $p;
     }
 
     /**
      * Plugin hook to alter SMTP authentication.
      * This is used if iTip messages are to be sent from an unauthenticated session
      */
     public function smtp_connect_hook($p)
     {
         // replace smtp auth settings if we're not in an authenticated session
         if ($this->itip_send && !$this->rc->user->ID) {
             foreach (array('smtp_server', 'smtp_user', 'smtp_pass') as $prop) {
                 $p[$prop] = $this->rc->config->get("calendar_itip_$prop", $p[$prop]);
             }
         }
 
       return $p;
     }
 
     /**
      * Helper function to build a Mail_mime object to send an iTip message
      *
      * @param array   Event object to send
      * @param string  iTip method (REQUEST|REPLY|CANCEL)
      * @param boolean Request RSVP
      * @return object Mail_mime object with message data
      */
     public function compose_itip_message($event, $method, $rsvp = true)
     {
         $from     = rcube_utils::idn_to_ascii($this->sender['email']);
         $from_utf = rcube_utils::idn_to_utf8($from);
         $sender   = format_email_recipient($from, $this->sender['name']);
 
         // truncate list attendees down to the recipient of the iTip Reply.
         // constraints for a METHOD:REPLY according to RFC 5546
         if ($method == 'REPLY') {
             $replying_attendee = null;
             $reply_attendees = array();
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['role'] == 'ORGANIZER') {
                     $reply_attendees[] = $attendee;
                 }
                 else if (strcasecmp($attendee['email'], $from) == 0 || strcasecmp($attendee['email'], $from_utf) == 0) {
                     $replying_attendee = $attendee;
                     if ($attendee['status'] != 'DELEGATED') {
                         unset($replying_attendee['rsvp']);  // unset the RSVP attribute
                     }
                 }
                 // include attendees relevant for delegation (RFC 5546, Section 4.2.5)
                 else if ((!empty($attendee['delegated-to']) &&
                             (strcasecmp($attendee['delegated-to'], $from) == 0 || strcasecmp($attendee['delegated-to'], $from_utf) == 0)) ||
                          (!empty($attendee['delegated-from']) &&
                             (strcasecmp($attendee['delegated-from'], $from) == 0 || strcasecmp($attendee['delegated-from'], $from_utf) == 0))) {
                     $reply_attendees[] = $attendee;
                 }
             }
             if ($replying_attendee) {
                 array_unshift($reply_attendees, $replying_attendee);
                 $event['attendees'] = $reply_attendees;
             }
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
         // set RSVP for every attendee
         else if ($method == 'REQUEST') {
             foreach ($event['attendees'] as $i => $attendee) {
                 if (($rsvp || !isset($attendee['rsvp'])) && ($attendee['status'] != 'DELEGATED' && $attendee['role'] != 'NON-PARTICIPANT')) {
                     $event['attendees'][$i]['rsvp']= (bool)$rsvp;
                 }
             }
         }
         else if ($method == 'CANCEL') {
             if ($event['recurrence']) {
                 unset($event['recurrence']['EXCEPTIONS']);
             }
         }
 
         // Set SENT-BY property if the sender is not the organizer
         if ($method == 'CANCEL' || $method == 'REQUEST') {
             foreach ((array)$event['attendees'] as $idx => $attendee) {
                 if ($attendee['role'] == 'ORGANIZER'
                     && $attendee['email']
                     && strcasecmp($attendee['email'], $from) != 0
                     && strcasecmp($attendee['email'], $from_utf) != 0
                 ) {
                     $attendee['sent-by'] = 'mailto:' . $from_utf;
                     $event['organizer'] = $event['attendees'][$idx] = $attendee;
                     break;
                 }
             }
         }
 
         // compose multipart message using PEAR:Mail_Mime
         $message = new Mail_mime("\r\n");
         $message->setParam('text_encoding', 'quoted-printable');
         $message->setParam('head_encoding', 'quoted-printable');
         $message->setParam('head_charset', RCUBE_CHARSET);
         $message->setParam('text_charset', RCUBE_CHARSET . ";\r\n format=flowed");
         $message->setContentType('multipart/alternative');
 
         // compose common headers array
         $headers = array(
             'From' => $sender,
             'Date' => $this->rc->user_date(),
             'Message-ID' => $this->rc->gen_message_id(),
             'X-Sender' => $from,
         );
         if ($agent = $this->rc->config->get('useragent')) {
             $headers['User-Agent'] = $agent;
         }
 
         $message->headers($headers);
 
         // attach ics file for this event
         $ical = libcalendaring::get_ical();
         $ics = $ical->export(array($event), $method, false, $method == 'REQUEST' && $this->plugin->driver ? array($this->plugin->driver, 'get_attachment_body') : false);
         $filename = $event['_type'] == 'task' ? 'todo.ics' : 'event.ics';
         $message->addAttachment($ics, 'text/calendar', $filename, false, '8bit', '', RCUBE_CHARSET . "; method=" . $method);
 
         return $message;
     }
 
     /**
      * Forward the given iTip event as delegation to another person
      *
      * @param array Event object to delegate
      * @param mixed Delegatee as string or hash array with keys 'name' and 'mailto'
      * @param boolean The delegator's RSVP flag
      * @param array List with indexes of new/updated attendees
      * @return boolean True on success, False on failure
      */
     public function delegate_to(&$event, $delegate, $rsvp = false, &$attendees = array())
     {
         if (is_string($delegate)) {
             $delegates = rcube_mime::decode_address_list($delegate, 1, false);
             if (count($delegates) > 0) {
                 $delegate = reset($delegates);
             }
         }
 
         $emails = $this->lib->get_user_emails();
         $me     = $this->rc->user->list_emails(true);
 
         // find/create the delegate attendee
         $delegate_attendee = array(
             'email' => $delegate['mailto'],
             'name'  => $delegate['name'],
             'role'  => 'REQ-PARTICIPANT',
         );
         $delegate_index = count($event['attendees']);
 
         foreach ($event['attendees'] as $i => $attendee) {
           // set myself the DELEGATED-TO parameter
           if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $event['attendees'][$i]['delegated-to'] = $delegate['mailto'];
               $event['attendees'][$i]['status'] = 'DELEGATED';
               $event['attendees'][$i]['role'] = 'NON-PARTICIPANT';
               $event['attendees'][$i]['rsvp'] = $rsvp;
 
               $me['email'] = $attendee['email'];
               $delegate_attendee['role'] = $attendee['role'];
           }
           // the disired delegatee is already listed as an attendee
           else if (stripos($delegate['mailto'], $attendee['email']) !== false && $attendee['role'] != 'ORGANIZER') {
               $delegate_attendee = $attendee;
               $delegate_index = $i;
               break;
           }
           // TODO: remove previous delegatee (i.e. attendee that has DELEGATED-FROM == $me)
         }
 
         // set/add delegate attendee with RSVP=TRUE and DELEGATED-FROM parameter
         $delegate_attendee['rsvp'] = true;
         $delegate_attendee['status'] = 'NEEDS-ACTION';
         $delegate_attendee['delegated-from'] = $me['email'];
         $event['attendees'][$delegate_index] = $delegate_attendee;
 
         $attendees[] = $delegate_index;
 
         $this->set_sender_email($me['email']);
         return $this->send_itip_message($event, 'REQUEST', $delegate_attendee, 'itipsubjectdelegatedto', 'itipmailbodydelegatedto');
     }
 
     /**
      * Handler for calendar/itip-status requests
      */
     public function get_itip_status($event, $existing = null)
     {
       $action = $event['rsvp'] ? 'rsvp' : '';
       $status = $event['fallback'];
       $latest = $rescheduled = false;
       $html   = '';
 
       if (is_numeric($event['changed']))
         $event['changed'] = new DateTime('@'.$event['changed']);
 
       // check if the given itip object matches the last state
       if ($existing) {
         $latest = (isset($event['sequence']) && intval($existing['sequence']) == intval($event['sequence'])) ||
                   (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] >= $event['changed']);
       }
 
       // determine action for REQUEST
       if ($event['method'] == 'REQUEST') {
         $html = html::div('rsvp-status', $this->gettext('acceptinvitation'));
 
         if ($existing) {
           $rsvp = $event['rsvp'];
           $emails = $this->lib->get_user_emails();
           foreach ($existing['attendees'] as $attendee) {
             if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
               $status = strtoupper($attendee['status']);
               break;
             }
           }
 
           // Detect re-sheduling
           if (!$latest) {
             // FIXME: This is probably to simplistic, or maybe we should just check
             //        attendee's RSVP flag in the new event?
             $rescheduled = $existing['start'] != $event['start'] || $existing['end'] > $event['end'];
           }
         }
         else {
           $rsvp = $event['rsvp'] && $this->rc->config->get('calendar_allow_itip_uninvited', true);
         }
 
         $status_lc = strtolower($status);
 
         if ($status_lc == 'unknown' && !$this->rc->config->get('calendar_allow_itip_uninvited', true)) {
           $html = html::div('rsvp-status', $this->gettext('notanattendee'));
           $action = 'import';
         }
         else if (in_array($status_lc, $this->rsvp_status)) {
           $status_text = $this->gettext(($latest ? 'youhave' : 'youhavepreviously') . $status_lc);
 
           if ($existing && ($existing['sequence'] > $event['sequence'] || (!isset($event['sequence']) && $existing['changed'] && $existing['changed'] > $event['changed']))) {
             $action = '';  // nothing to do here, outdated invitation
             if ($status_lc == 'needs-action')
               $status_text = $this->gettext('outdatedinvitation');
           }
           else if (!$existing && !$rsvp) {
             $action = 'import';
           }
           else if ($rescheduled) {
             $action = 'rsvp';
           }
           else if ($status_lc != 'needs-action') {
             // check if there are any changes
             if ($latest) {
               $diff   = $this->get_itip_diff($event, $existing);
               $latest = empty($diff);
             }
 
             $action = !$latest ? 'update' : '';
           }
 
           $html = html::div('rsvp-status ' . $status_lc, $status_text);
         }
       }
       // determine action for REPLY
       else if ($event['method'] == 'REPLY') {
         // check whether the sender already is an attendee
         if ($existing) {
           $action = $this->rc->config->get('calendar_allow_itip_uninvited', true) ? 'accept' : '';
           $listed = false;
           foreach ($existing['attendees'] as $attendee) {
             if ($attendee['role'] != 'ORGANIZER' && strcasecmp($attendee['email'], $event['attendee']) == 0) {
               $status_lc = strtolower($status);
               if (in_array($status_lc, $this->rsvp_status)) {
                 $html = html::div('rsvp-status ' . $status_lc, $this->gettext(array(
                     'name' => 'attendee' . $status_lc,
                     'vars' => array(
                         'delegatedto' => rcube::Q($event['delegated-to'] ?: ($attendee['delegated-to'] ?: '?')),
                     )
                 )));
               }
               $action = $attendee['status'] == $status || !$latest ? '' : 'update';
               $listed = true;
               break;
             }
           }
 
           if (!$listed) {
             $html = html::div('rsvp-status', $this->gettext('itipnewattendee'));
           }
         }
         else {
           $html = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
           $action = '';
         }
       }
       else if ($event['method'] == 'CANCEL') {
         if (!$existing) {
           $html = html::div('rsvp-status hint', $this->gettext('itipobjectnotfound'));
           $action = '';
         }
       }
 
       return array(
           'uid'        => $event['uid'],
           'id'         => asciiwords($event['uid'], true),
           'existing'   => $existing ? true : false,
           'saved'      => $existing ? true : false,
           'latest'     => $latest,
           'status'     => $status,
           'action'     => $action,
           'rescheduled' => $rescheduled,
           'html'       => $html,
       );
     }
 
     protected function get_itip_diff($event, $existing)
     {
         if (empty($event) || empty($existing) || empty($event['message_uid'])) {
             return;
         }
 
         $itip = $this->lib->mail_get_itip_object($event['mbox'], $event['message_uid'], $event['mime_id'],
             $event['task'] == 'calendar' ? 'event' : 'task');
 
         if ($itip) {
             // List of properties that could change without SEQUENCE bump
             $attrs = array('description', 'title', 'location', 'url');
             $diff  = array();
 
             foreach ($attrs as $attr) {
                 if (isset($itip[$attr]) && $itip[$attr] != $existing[$attr]) {
                     $diff[$attr] = array(
                         'new' => $itip[$attr],
                         'old' => $existing[$attr]
                     );
                 }
             }
 
             $status             = array();
             $itip_attendees     = array();
             $existing_attendees = array();
             $emails             = $this->lib->get_user_emails();
 
             // Compare list of attendees (ignoring current user status)
             foreach ((array) $existing['attendees'] as $idx => $attendee) {
                 if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
                     $status[strtolower($attendee['email'])] = $attendee['status'];
                 }
                 if ($attendee['role'] == 'ORGANIZER') {
                     $attendee['status'] = 'ACCEPTED'; // sometimes is not set for exceptions
                     $existing['attendees'][$idx] = $attendee;
                 }
                 $existing_attendees[] = $attendee['email'].$attendee['name'];
             }
             foreach ((array) $itip['attendees'] as $idx => $attendee) {
                 if ($attendee['email'] && ($_status = $status[strtolower($attendee['email'])])) {
                     $attendee['status'] = $_status;
                     $itip['attendees'][$idx] = $attendee;
                 }
                 $itip_attendees[] = $attendee['email'].$attendee['name'];
             }
 
             if ($itip_attendees != $existing_attendees) {
                 $diff['attendees'] = array(
                     'new' => $itip['attendees'],
                     'old' => $existing['attendees']
                 );
             }
 
             return $diff;
         }
     }
 
     /**
      * Build inline UI elements for iTip messages
      */
     public function mail_itip_inline_ui($event, $method, $mime_id, $task, $message_date = null, $preview_url = null)
     {
         $buttons = array();
         $dom_id = asciiwords($event['uid'], true);
         $rsvp_status = 'unknown';
 
         // pass some metadata about the event and trigger the asynchronous status check
         $changed = is_object($event['changed']) ? $event['changed'] : $message_date;
         $metadata = array(
             'uid'      => $event['uid'],
             '_instance' => $event['_instance'],
             'changed'  => $changed ? $changed->format('U') : 0,
             'sequence' => intval($event['sequence']),
             'method'   => $method,
             'task'     => $task,
             'mime_id'  => $mime_id,
         );
 
         // create buttons to be activated from async request checking existence of this event in local calendars
         $buttons[] = html::div(array('id' => 'loading-'.$dom_id, 'class' => 'rsvp-status loading'), $this->gettext('loading'));
 
         // on iTip REPLY we have two options:
         if ($method == 'REPLY') {
             $title = $this->gettext('itipreply');
 
             foreach ($event['attendees'] as $attendee) {
                 if (!empty($attendee['email']) && $attendee['role'] != 'ORGANIZER') {
                     if (empty($event['_sender']) || self::compare_email($attendee['email'], $event['_sender'], $event['_sender_utf'])) {
                         $metadata['attendee'] = $attendee['email'];
                         $rsvp_status = strtoupper($attendee['status']);
                         if ($attendee['delegated-to']) {
                             $metadata['delegated-to'] = $attendee['delegated-to'];
                         }
                         break;
                     }
                 }
             }
 
             // 1. update the attendee status on our copy
             $update_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('updateattendeestatus'),
             ));
 
             // 2. accept or decline a new or delegate attendee
             $accept_buttons = html::tag('input', array(
                 'type' => 'button',
                 'class' => "button accept",
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('acceptattendee'),
             ));
             $accept_buttons .= html::tag('input', array(
                 'type' => 'button',
                 'class' => "button decline",
                 'onclick' => "rcube_libcalendaring.decline_attendee_reply('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('declineattendee'),
             ));
 
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
             $buttons[] = html::div(array('id' => 'accept-'.$dom_id, 'style' => 'display:none'), $accept_buttons);
         }
         // when receiving iTip REQUEST messages:
         else if ($method == 'REQUEST') {
             $emails = $this->lib->get_user_emails();
             $title = $event['sequence'] > 0 ? $this->gettext('itipupdate') : $this->gettext('itipinvitation');
             $metadata['rsvp'] = true;
             $metadata['sensitivity'] = $event['sensitivity'];
 
             if (is_object($event['start'])) {
                 $metadata['date'] = $event['start']->format('U');
             }
 
             // check for X-KOLAB-INVITATIONTYPE property and only show accept/decline buttons
             if (self::get_custom_property($event, 'X-KOLAB-INVITATIONTYPE') == 'CONFIRMATION') {
                 $this->rsvp_actions = array('accepted','declined');
                 $metadata['nosave'] = true;
             }
 
             // 1. display RSVP buttons (if the user was invited)
             foreach ($this->rsvp_actions as $method) {
                 $rsvp_buttons .= html::tag('input', array(
                     'type' => 'button',
                     'class' => "button $method",
                     'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task', '$method', '$dom_id')",
                     'value' => $this->gettext('itip' . $method),
                 ));
             }
 
             // add button to open calendar/preview
             if (!empty($preview_url)) {
               $msgref = $this->lib->ical_message->folder . '/' . $this->lib->ical_message->uid . '#' . $mime_id;
               $rsvp_buttons .= html::tag('input', array(
                   'type' => 'button',
                   'class' => "button preview",
                   'onclick' => "rcube_libcalendaring.open_itip_preview('" . rcube::JQ($preview_url) . "', '" . rcube::JQ($msgref) . "')",
                   'value' => $this->gettext('openpreview'),
               ));
             }
 
             // 2. update the local copy with minor changes
             $update_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('updatemycopy'),
             ));
 
             // 3. Simply import the event without replying
             $import_button = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
                 'value' => $this->gettext('importtocalendar'),
             ));
 
             // check my status
             foreach ($event['attendees'] as $attendee) {
                 if ($attendee['email'] && in_array(strtolower($attendee['email']), $emails)) {
                     $metadata['attendee'] = $attendee['email'];
                     $metadata['rsvp'] = $attendee['rsvp'] || $attendee['role'] != 'NON-PARTICIPANT';
                     $rsvp_status = !empty($attendee['status']) ? strtoupper($attendee['status']) : 'NEEDS-ACTION';
                     break;
                 }
             }
 
             // add itip reply message controls
             $rsvp_buttons .= html::div('itip-reply-controls', $this->itip_rsvp_options_ui($dom_id, $metadata['nosave']));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'class' => 'rsvp-buttons', 'style' => 'display:none'), $rsvp_buttons);
             $buttons[] = html::div(array('id' => 'update-'.$dom_id, 'style' => 'display:none'), $update_button);
 
             // prepare autocompletion for delegation dialog
             if (in_array('delegated', $this->rsvp_actions)) {
                 $this->rc->autocomplete_init();
             }
         }
         // for CANCEL messages, we can:
         else if ($method == 'CANCEL') {
             $title = $this->gettext('itipcancellation');
             $event_prop = array_filter(array(
               'uid' => $event['uid'],
               '_instance' => $event['_instance'],
               '_savemode' => $event['_savemode'],
             ));
 
             // 1. remove the event from our calendar
             $button_remove = html::tag('input', array(
                 'type' => 'button',
                 'class' => 'button',
                 'onclick' => "rcube_libcalendaring.remove_from_itip(" . rcube_output::json_serialize($event_prop) . ", '$task', '" . rcube::JQ($event['title']) . "')",
                 'value' => $this->gettext('removefromcalendar'),
             ));
 
             // 2. update our copy with status=cancelled
             $button_update = html::tag('input', array(
               'type' => 'button',
               'class' => 'button',
               'onclick' => "rcube_libcalendaring.add_from_itip_mail('" . rcube::JQ($mime_id) . "', '$task')",
               'value' => $this->gettext('updatemycopy'),
             ));
 
             $buttons[] = html::div(array('id' => 'rsvp-'.$dom_id, 'style' => 'display:none'), $button_remove . $button_update);
 
             $rsvp_status = 'CANCELLED';
             $metadata['rsvp'] = true;
         }
 
         // append generic import button
         if ($import_button) {
             $buttons[] = html::div(array('id' => 'import-'.$dom_id, 'style' => 'display:none'), $import_button);
         }
 
         // pass some metadata about the event and trigger the asynchronous status check
         $metadata['fallback'] = $rsvp_status;
         $metadata['rsvp'] = intval($metadata['rsvp']);
 
         $this->rc->output->add_script("rcube_libcalendaring.fetch_itip_object_status(" . rcube_output::json_serialize($metadata) . ")", 'docready');
 
         // get localized texts from the right domain
         foreach (array('savingdata','deleteobjectconfirm','declinedeleteconfirm','declineattendee',
             'cancel','itipdelegated','declineattendeeconfirm','itipcomment','delegateinvitation',
             'delegateto','delegatersvpme','delegateinvalidaddress') as $label) {
           $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
         }
 
         // show event details with buttons
         return $this->itip_object_details_table($event, $title) .
             html::div(array('class' => 'itip-buttons', 'id' => 'itip-buttons-' . asciiwords($metadata['uid'], true)), join('', $buttons));
     }
 
     /**
      * Render an RSVP UI widget with buttons to respond on iTip invitations
      */
     function itip_rsvp_buttons($attrib = array(), $actions = null)
     {
         $attrib += array('type' => 'button');
 
         if (!$actions)
             $actions = $this->rsvp_actions;
 
         foreach ($actions as $method) {
             $buttons .= html::tag('input', array(
                 'type'  => $attrib['type'],
                 'name'  => $attrib['iname'],
                 'class' => 'button',
                 'rel'   => $method,
                 'value' => $this->gettext('itip' . $method),
             ));
         }
 
         // add localized texts for the delegation dialog
         if (in_array('delegated', $actions)) {
             foreach (array('itipdelegated','itipcomment','delegateinvitation',
                   'delegateto','delegatersvpme','delegateinvalidaddress','cancel') as $label) {
                 $this->rc->output->command('add_label', "itip.$label", $this->gettext($label));
             }
         }
 
         foreach (array('all','current','future') as $mode) {
             $this->rc->output->command('add_label', "rsvpmode$mode", $this->gettext("rsvpmode$mode"));
         }
 
         $savemode_radio = new html_radiobutton(array('name' => '_rsvpmode', 'class' => 'rsvp-replymode'));
 
         return html::div($attrib,
             html::div('label', $this->gettext('acceptinvitation')) .
             html::div('rsvp-buttons',
                 $buttons .
                 html::div('itip-reply-controls', $this->itip_rsvp_options_ui($attrib['id']))
             )
         );
     }
 
     /**
      * Render UI elements to control iTip reply message sending
      */
     public function itip_rsvp_options_ui($dom_id, $disable = false)
     {
         $itip_sending = $this->rc->config->get('calendar_itip_send_option', 3);
 
         // itip sending is entirely disabled
         if ($itip_sending === 0) {
             return '';
         }
         // add checkbox to suppress itip reply message
         else if ($itip_sending >= 2) {
             $rsvp_additions = html::label(array('class' => 'noreply-toggle'),
                 html::tag('input', array('type' => 'checkbox', 'id' => 'noreply-'.$dom_id, 'value' => 1, 'disabled' => $disable, 'checked' => ($itip_sending & 1) == 0))
                 . ' ' . $this->gettext('itipsuppressreply')
             );
         }
 
         // add input field for reply comment
         $toggle_attrib = array(
             'href'    => '#toggle',
             'class'   => 'reply-comment-toggle',
             'onclick' => '$(this).hide().parent().find(\'textarea\').show().focus()'
         );
         $textarea_attrib = array(
             'id'    => 'reply-comment-' . $dom_id,
             'name'  => '_comment',
             'cols'  => 40,
             'rows'  => 6,
             'style' => 'display:none',
             'placeholder' => $this->gettext('itipcomment')
         );
 
         $rsvp_additions .= html::a($toggle_attrib, $this->gettext('itipeditresponse'))
             . html::div('itip-reply-comment', html::tag('textarea', $textarea_attrib, ''));
 
         return $rsvp_additions;
     }
 
     /**
      * Render event/task details in a table
      */
     function itip_object_details_table($event, $title)
     {
         $table = new html_table(array('cols' => 2, 'border' => 0, 'class' => 'calendar-eventdetails'));
         $table->add('ititle', $title);
         $table->add('title', rcube::Q($event['title']));
         if ($event['start'] && $event['end']) {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         else if ($event['due'] && $event['_type'] == 'task') {
             $table->add('label', $this->gettext('date'));
             $table->add('date', rcube::Q($this->lib->event_date_text($event)));
         }
         if (!empty($event['recurrence_date'])) {
             $table->add('label', '');
             $table->add('recurrence-id', $this->gettext($event['thisandfuture'] ? 'itipfutureoccurrence' : 'itipsingleoccurrence'));
         }
         else if (!empty($event['recurrence'])) {
             $table->add('label', $this->gettext('recurring'));
             $table->add('recurrence', $this->lib->recurrence_text($event['recurrence']));
         }
         if ($event['location'] && trim($event['location'])) {
             $table->add('label', $this->gettext('location'));
             $table->add('location', rcube::Q($event['location']));
         }
         if ($event['sensitivity'] && !preg_match('/^(x-|public$)/i', $event['sensitivity'])) {
             $table->add('label', $this->gettext('sensitivity'));
             $table->add('sensitivity', ucfirst($this->gettext($event['sensitivity'])) . '!');
         }
         if ($event['status'] == 'COMPLETED' || $event['status'] == 'CANCELLED') {
             $table->add('label', $this->gettext('status'));
             $table->add('status', $this->gettext('status-' . strtolower($event['status'])));
         }
         if ($event['comment'] && trim($event['comment'])) {
             $table->add('label', $this->gettext('comment'));
             $table->add('location', rcube::Q($event['comment']));
         }
 
         return $table->show();
     }
 
 
     /**
      * Create iTIP invitation token for later replies via URL
      *
      * @param array Hash array with event properties
      * @param string Attendee email address
      * @return string Invitation token
      */
     public function store_invitation($event, $attendee)
     {
         // empty stub
         return false;
     }
 
     /**
      * Mark invitations for the given event as cancelled
      *
      * @param array Hash array with event properties
      */
     public function cancel_itip_invitation($event)
     {
         // empty stub
         return false;
     }
 
     /**
      * Utility function to get the value of a custom property
      */
     public static function get_custom_property($event, $name)
     {
       $ret = false;
 
       if (is_array($event['x-custom'])) {
           array_walk($event['x-custom'], function($prop, $i) use ($name, &$ret) {
               if (strcasecmp($prop[0], $name) === 0) {
                   $ret = $prop[1];
               }
           });
       }
 
       return $ret;
     }
 
     /**
      * Compare email address
      */
     public static function compare_email($value, $email, $email_utf = null)
     {
         $v1 = !empty($email) && strcasecmp($value, $email) === 0;
         $v2 = !empty($email_utf) && strcasecmp($value, $email_utf) === 0;
 
         return $v1 || $v2;
     }
 }
diff --git a/plugins/tasklist/localization/en_US.inc b/plugins/tasklist/localization/en_US.inc
index d34f17de..6d40b10a 100644
--- a/plugins/tasklist/localization/en_US.inc
+++ b/plugins/tasklist/localization/en_US.inc
@@ -1,215 +1,215 @@
 <?php
 
 /**
  * Localizations for the Kolab Tasks plugin
  *
  * Copyright (C) 2014, Kolab Systems AG
  *
  * For translation see https://www.transifex.com/projects/p/kolab/resource/tasklist/
  */
 
 $labels = array();
 $labels['navtitle'] = 'Tasks';
 $labels['lists'] = 'Tasklists';
 $labels['list'] = 'Tasklist';
 $labels['tags'] = 'Tags';
 $labels['export'] = 'Export';
 $labels['exporttitle'] = 'Export to iCalendar';
 $labels['exportattachments'] = 'With attachments';
 $labels['currentview'] = 'current view';
 $labels['tasklistsubscribe'] = 'List permanently';
 $labels['listsearchresults'] = 'Available Tasklists';
 $labels['findlists'] = 'Find tasklists...';
 $labels['searchterms'] = 'Search terms';
 $labels['notasklistsfound'] = 'No tasklists found';
 $labels['nrtasklistsfound'] = '$nr tasklists found';
 $labels['removelist'] = 'Remove from list';
 $labels['showcaldavurl'] = 'Show CalDAV URL';
 $labels['caldavurldescription'] = 'Copy this address to a <a href="http://en.wikipedia.org/wiki/CalDAV" target="_blank">CalDAV</a> client application (e.g. Evolution or Mozilla Thunderbird) to synchronize this specific tasklist with your computer or mobile device.';
 
 $labels['newtask'] = 'New Task';
 $labels['createtask'] = 'Create Task <Enter>';
 $labels['createnewtask'] = 'Create new Task (e.g. Saturday, Mow the lawn)';
 $labels['createfrommail'] = 'Save as task';
 $labels['printtitle'] = 'Print tasks';
 $labels['printdescriptions'] = 'Print descriptions';
 $labels['mark'] = 'Mark';
 $labels['unmark'] = 'Unmark';
 $labels['edit'] = 'Edit';
 $labels['delete'] = 'Delete';
 $labels['title'] = 'Title';
 $labels['description'] = 'Description';
 $labels['datetime'] = 'Due';
 $labels['duetime'] = 'Due time';
 $labels['start'] = 'Start';
 $labels['starttime'] = 'Start time';
 $labels['alarms'] = 'Reminder';
 $labels['repeat'] = 'Repeat';
 $labels['links'] = 'Reference';
 $labels['status'] = 'Status';
 $labels['status-needs-action'] = 'Needs action';
 $labels['status-in-process'] = 'In process';
 $labels['status-completed'] = 'Completed';
 $labels['status-cancelled'] = 'Cancelled';
 $labels['assignedto'] = 'Assigned to';
 $labels['created'] = 'Created';
 $labels['changed'] = 'Last Modified';
 $labels['taskoptions'] = 'Options';
 
 $labels['all'] = 'All';
 $labels['flagged'] = 'Flagged';
 $labels['complete'] = 'Complete';
 $labels['completeness'] = 'Progress';
 $labels['overdue'] = 'Overdue';
 $labels['today'] = 'Today';
 $labels['tomorrow'] = 'Tomorrow';
 $labels['next7days'] = 'Next 7 days';
 $labels['later'] = 'Later';
 $labels['assigned'] = 'Assigned';
 $labels['assignedtitle'] = 'Tasks you assigned to others';
 $labels['mytasks'] = 'My tasks';
 $labels['mytaskstitle'] = 'Tasks assigned to you';
 $labels['nodate'] = 'no date';
 $labels['removetag'] = 'Remove';
 $labels['removelink'] = 'Remove email reference';
 $labels['auto'] = 'Auto';
 
 $labels['taskdetails'] = 'Details';
 $labels['newtask'] = 'New Task';
 $labels['edittask'] = 'Edit Task';
 $labels['save'] = 'Save';
 $labels['cancel'] = 'Cancel';
 $labels['saveandnotify'] = 'Save and Notify';
 $labels['addsubtask'] = 'Add subtask';
 $labels['deletetask'] = 'Delete task';
 $labels['deletethisonly'] = 'Delete this task only';
 $labels['deletewithchilds'] = 'Delete with all subtasks';
 $labels['taskactions'] = 'Task options...';
 
 $labels['tabsummary'] = 'Summary';
 $labels['tabrecurrence'] = 'Recurrence';
 $labels['tabassignments'] = 'Assignments';
 $labels['tabattachments'] = 'Attachments';
 $labels['tabsharing'] = 'Sharing';
 
 $labels['editlist'] = 'Edit list';
 $labels['createlist'] = 'Add list';
 $labels['listactions'] = 'List options...';
 $labels['listname'] = 'Name';
 $labels['showalarms'] = 'Show reminders';
 $labels['import'] = 'Import';
 $labels['viewactions'] = 'View actions';
 $labels['focusview'] = 'View only this list';
 
 // date words
 $labels['on'] = 'on';
 $labels['at'] = 'at';
 $labels['this'] = 'this';
 $labels['next'] = 'next';
 $labels['yes'] = 'yes';
 
 // messages
 $labels['savingdata'] = 'Saving data...';
 $labels['errorsaving'] = 'Failed to save data.';
 $labels['notasksfound'] = 'No tasks found for the given criteria';
 $labels['invalidstartduedates'] = 'Start date must not be greater than due date.';
 $labels['invalidstartduetimes'] = 'Start and due dates must either both or none specify a time.';
 $labels['recurrencerequiresdate'] = 'Recurring tasks require either a start or due date.';
 $labels['deletetasktconfirm'] = 'Do you really want to delete this task?';
 $labels['deleteparenttasktconfirm'] = 'Do you really want to delete this task and all its subtasks?';
 $labels['deletelistconfirm'] = 'Do you really want to delete this list with all its tasks?';
 $labels['deletelistconfirmrecursive'] = 'Do you really want to delete this list with all its sub-lists and tasks?';
 $labels['aclnorights'] = 'You do not have administrator rights on this task list.';
 $labels['changetaskconfirm'] = 'Update task';
 $labels['changeconfirmnotifications'] = 'Do you want to notify the attendees about the modification?';
 $labels['partstatupdatenotification'] = 'Do you want to notify the organizer about the status change?';
 
 // (hidden) titles and labels for accessibility annotations
 $labels['quickaddinput'] = 'New task date and title';
 $labels['arialabelquickaddbox'] = 'Quick add new task';
 $labels['arialabelsearchform'] = 'Task search form';
 $labels['arialabelquicksearchbox'] = 'Task search input';
 $labels['arialabellistsearchform'] = 'Tasklists search form';
 $labels['arialabeltaskselector'] = 'List mode';
 $labels['arialabeltasklisting'] = 'Tasks listing';
 
 // attendees
 $labels['attendee'] = 'Assignee';
 $labels['role'] = 'Role';
 $labels['availability'] = 'Avail.';
 $labels['confirmstate'] = 'Status';
 $labels['addattendee'] = 'Add assignee';
 $labels['roleorganizer'] = 'Organizer';
 $labels['rolerequired'] = 'Required';
 $labels['roleoptional'] = 'Optional';
 $labels['rolechair'] = 'Chair';
 $labels['rolenonparticipant'] = 'Observer';
 $labels['sendinvitations'] = 'Send invitations';
 $labels['sendnotifications'] = 'Notify assignees about modifications';
 $labels['sendcancellation'] = 'Notify assignees about task cancellation';
 $labels['invitationsubject'] = 'You\'ve been assigned to "$title"';
-$labels['invitationmailbody'] = "*\$title*\n\nDue: \$date\n\nAssignees: \$attendees\n\nPlease find attached an iCalendar file with all the task details which you can import to your tasks application.";
+$labels['invitationmailbody'] = "*\$title*\n\nDue: \$date\n\nAssignees: \$attendees\n\n\$description\n\nPlease find attached an iCalendar file with all the task details which you can import to your tasks application.";
 $labels['itipupdatesubject'] = '"$title" has been updated';
 $labels['itipupdatesubjectempty'] = 'A task that concerns you has been updated';
 $labels['itipupdatemailbody'] = "*\$title*\n\nDue: \$date\n\nAssignees: \$attendees\n\nPlease find attached an iCalendar file with the updated task details which you can import to your tasks application.";
 $labels['itipcancelsubject'] = '"$title" has been cancelled';
 $labels['itipcancelmailbody'] = "*\$title*\n\nDue: \$date\n\nAssignees: \$attendees\n\nThe task has been cancelled by \$organizer.\n\nPlease find attached an iCalendar file with the updated task details.";
 $labels['saveintasklist'] = 'save in ';
 
 // history dialog
 $labels['taskhistory'] = 'History';
 $labels['objectchangelog'] = 'Change History';
 $labels['objectdiff'] = 'Changes from $rev1 to $rev2';
 $labels['objectnotfound'] = 'Failed to load task data';
 $labels['objectchangelognotavailable'] = 'Change history is not available for this task';
 $labels['objectdiffnotavailable'] = 'No comparison possible for the selected revisions';
 $labels['revisionrestoreconfirm'] = 'Do you really want to restore revision $rev of this task? This will replace the current task with the old version.';
 $labels['objectrestoresuccess'] = 'Revision $rev successfully restored';
 $labels['objectrestoreerror'] = 'Failed to restore the old revision';
 
 // invitation handling (overrides labels from libcalendaring)
 $labels['itipobjectnotfound'] = 'The task referred by this message was not found in your tasks list.';
 
 $labels['itipmailbodyaccepted'] = "\$sender has accepted the assignment to the following task:\n\n*\$title*\n\nDue: \$date\n\nAssignees: \$attendees";
 $labels['itipmailbodytentative'] = "\$sender has tentatively accepted the assignment to the following task:\n\n*\$title*\n\nDue: \$date\n\nAssignees: \$attendees";
 $labels['itipmailbodydeclined'] = "\$sender has declined the assignment to the following task:\n\n*\$title*\n\nDue: \$date\n\nAssignees: \$attendees";
 $labels['itipmailbodycancel'] = "\$sender has rejected your assignment to the following task:\n\n*\$title*\n\nDue: \$date";
 $labels['itipmailbodyin-process'] = "\$sender has set the status of the following task to in-process:\n\n*\$title*\n\nDue: \$date";
 $labels['itipmailbodycompleted'] = "\$sender has completed the following task:\n\n*\$title*\n\nDue: \$date";
 $labels['itipmailbodydelegated'] = "\$sender has delegated the following task:\n\n*\$title*\n\nDue: \$date";
 $labels['itipmailbodydelegatedto'] = "\$sender has delegated the following task to you:\n\n*\$title*\n\nDue: \$date";
 
 $labels['attendeeaccepted'] = 'Assignee has accepted';
 $labels['attendeetentative'] = 'Assignee has tentatively accepted';
 $labels['attendeedeclined'] = 'Assignee has declined';
 $labels['attendeedelegated'] = 'Assignee has delegated to $delegatedto';
 $labels['attendeein-process'] = 'Assignee is in-process';
 $labels['attendeecompleted'] = 'Assignee has completed';
 
 $labels['acceptinvitation'] = 'Do you accept this assignment?';
 $labels['itipdeclinetask'] = 'Decline your assignment to this task to the organizer';
 $labels['declinedeleteconfirm'] = 'Do you also want to delete this declined task from your tasks list?';
 $labels['itipcomment'] = 'Invitation/notification comment';
 $labels['itipcommenttitle'] = 'This comment will be attached to the invitation/notification message sent to assignees';
 $labels['itipsendsuccess'] = 'Notification sent to assignees';
 $labels['errornotifying'] = 'Failed to send notifications to task assignees';
 $labels['removefromcalendar'] = 'Remove from my tasks';
 $labels['delegateinvitation'] = 'Delegate assignment';
 
 $labels['andnmore'] = '$nr more...';
 $labels['savetotasklist'] = 'Save to tasks';
 $labels['comment'] = 'Comment';
 $labels['errorimportingtask'] = 'Failed to import task(s)';
 $labels['importwarningexists'] = 'A copy of this task already exists in your tasklist.';
 $labels['importsuccess'] = 'Successfully imported $nr tasks';
 $labels['newerversionexists'] = 'A newer version of this task already exists! Aborted.';
 $labels['nowritetasklistfound'] = 'No tasklist found to save the task';
 $labels['importedsuccessfully'] = 'The task was successfully added to \'$list\'';
 $labels['updatedsuccessfully'] = 'The task was successfully updated in \'$list\'';
 $labels['attendeupdateesuccess'] = 'Successfully updated the participant\'s status';
 $labels['itipresponseerror'] = 'Failed to send the response to this task assignment';
 $labels['itipinvalidrequest'] = 'This invitation is no longer valid';
 $labels['sentresponseto'] = 'Successfully sent assignment response to $mailto';
 $labels['successremoval'] = 'The task has been deleted successfully.';
 $labels['invalidlistproperties'] = 'Invalid list properties! Please set a valid name.';
 $labels['arialabelsortmenu'] = 'Tasks sorting options';