Hi Marco, to use external authentication like Kerberos you have to use HTTP Header in front of SOGo: http://www.sogo.nu/english/support/faq/article/how-to-use-webauth-with-sogo-2.html
There are a lot of examples in the Web for doing that. But the exact configuration steps depend on your setup. Especially for Apache and Kerberos there are a lot of how-tos. esco -- [email protected] https://inverse.ca/sogo/lists
