Basic: Debian Linux

1. Add the following two lines to /etc/apt/sources.list.d/kolab.list:

   
   For Debian Wheezy:

   deb http://obs.kolabsys.com:82/Kolab:/3.2/Debian_7.0/ ./ deb http://obs.kolabsys.com:82/Kolab:/3.2:/Updates/Debian_7.0/ ./

Quelle: Install on Debian

and more:

HOWTO: Multi-Domain Support in Kolab