Thanks for your help, I wanted no dropdownlist, but that's a little complicated with more then one mailserver, i guess.
(I'm not a programmer). After all. i decided to work with a dropdownlist
, which works fine.
So, now i use one single RoundCube installation (for maintenance), from which i can access every ISPConfig3-server in my network. My RoundCube installation can be visited form every website when the suffix /webmail has been added or by clicking the Webmail icon in the ISPConfig3 controlpanel.