Hey,
so, I presumed you were using the default mailback template. Also, for the form name, since it's case sensitive, I don't know if its name is kontakt or Kontakt. So please adjust it in the next part.
Navigate to /media/breezingforms/mailtpl. Create a new file there called (and this is the case sensitive part)
Kontakt_mailback.txt.php, so if your form name is kontakt, then it's kontakt_mailback...
Inside it, please paste the following code. I kept the default structure except for the checkbox group you needed.
<?php
/**
* BreezingForms - A Joomla Forms Application
* @version 1.7.3
* @package BreezingForms
* @copyright (C) 2008-2011 by Markus Bopp
* @license Released under the terms of the GNU General Public License
**/
defined('_JEXEC') or die('Direct Access to this location is not allowed.');
?>
<?php if ($RECORD_ID != ''): ?>
<?php echo $PROCESS_RECORDSAVEDID?> <?php echo $RECORD_ID ?><?php echo $NL ?>
<?php endif; ?>
<?php echo $PROCESS_FORMID?>: <?php echo $FORM ?><?php echo $NL ?>
<?php echo $PROCESS_FORMTITLE ?>: <?php echo $TITLE ?><?php echo $NL ?>
<?php echo $PROCESS_FORMNAME ?>: <?php echo $NAME ?><?php echo $NL ?>
<?php echo $PROCESS_SUBMITTEDAT ?>: <?php echo $SUBMITTED ?><?php echo $NL ?>
<?php echo $PROCESS_SUBMITTERIP ?>: <?php echo $IP ?><?php echo $NL ?>
<?php echo $PROCESS_SUBMITTERID ?>: <?php echo $SUBMITTERID ?><?php echo $NL ?>
<?php echo $PROCESS_SUBMITTERUSERNAME ?>: <?php echo $SUBMITTERUSERNAME ?><?php echo $NL ?>
<?php echo $PROCESS_SUBMITTERFULLNAME ?>: <?php echo $SUBMITTERFULLNAME ?><?php echo $NL ?>
<?php echo $PROCESS_PROVIDER ?>: <?php echo $PROVIDER ?><?php echo $NL ?>
<?php echo $PROCESS_BROWSER ?>: <?php echo $BROWSER ?><?php echo $NL ?>
<?php echo $PROCESS_OPSYS ?>: <?php echo $OPSYS ?><?php echo $NL ?>
<?php foreach ($MAILDATA as $DATA): ?>
<?php if ($DATA[_FF_DATA_NAME] == 'IhreAuswahl'): ?>
<?php $all = explode(',', $DATA[_FF_DATA_VALUE]); $tmp = str_replace(' ', '', $all); echo $DATA[_FF_DATA_TITLE]?>: <?php echo implode($NL, $tmp); echo $NL;?>
<?php else: ?>
<?php echo $DATA[_FF_DATA_TITLE]?>: <?php echo $DATA[_FF_DATA_VALUE]?><?php echo $NL ?>
<?php endif; ?>
<?php endforeach; ?>
So, adjust this to your needs if you don't want the part with the technical details about form ID, title, IP etc. The important part is starting with <?php foreach...
If you have trouble implementing this, you can send backend credentials to darko.cujic@crosstec.org and I'll do it for you.
Kind regards,
Darko