I inherited the OTRS ticket system three years ago and have left it (and the server it is running on) mostly alone. Time marches on however and after upgrading the Ubuntu server last week the system stopped receiving emails. It produces this error:

(note: i happily relinquish privacy)
The problem seems to be the ticket_answered bit, but its immune to my google-fu. Trying to send the problem-email-hash via Postmaster.pl returns an error as well.
Ive no idea what to do, while in the mean time my department isnt receiving calls as they get swiped from the server.
If you, dear reader, can bail me out, i'd be eternally grateful. Please consider in your response that when it comes to me and Linux, it helps to assume I am a six year old child freshly fished out of the jungle.