Am Mittwoch, 19. Oktober 2011, um 08.15:49 schrieb A.L.E.C:

> On 18.10.2011 22:17, Andreas Dick wrote:
> > security error: content at http://realserver.ch/roundcube/ is not allowed
> > to load data from von http://niceurl.ch/
>
> // X-Frame-Options HTTP header value sent to prevent from Clickjacking.
> // Possible values: sameorigin|deny. Set to false in order to disable
> sending them
> $rcmail_config['x_frame_options'] = 'sameorigin';

thanks ALEC!
this was the problem... I did not understand this feature, now I do :-)
Andreas