Mail exchange record

Provide a mail exchange record pointing to mx1.hdm-stuttgart.de. Test this configuration using dig accordingly.

Caveat: Configuring a client machine using your name server and sending a mail to xy123@mi.hdm-stuttgart.de won't work since the HdM's mail filters will deliver these mails to the MI mail server mail.mi.hdm-stuttgart.de rather than to mail.hdm-stuttgart.de (and you probably have no account on this particular machine). In addition both servers will reject mails having destination addresses differing from ...@hdm-stuttgart.de or ...@mi.hdm-stuttgart.de respectively.