Thre is an autoconfiguration feature in Thunderbird in order to make it easier for the users to set up their mail accounts. Read more at Autoconfiguration in Thunderbird at the Mozilla web docs.
BMC-IT has a server at autoconfig.bmc.uu.se. To configure the feature for your domain at the university just add the following to your zone.
autoconfig IN CNAME autoconfig.bmc.uu.se.
The record may look like this in BlueCat: