[otrs] Using SQL to Delete Tickets

Hey Folks... Just a warning.. prior to this morning I had no idea what CS was using here to track issues. But since the guy who set it up and maintains it is in Seattle today.. I was asked to take a look at an issue. So please forgive my ignorance. My question is pretty basic.. there are a ton of tickets in our OTRS that are mailer-daemon responses. We want to get rid of them. Can I just go into the tickets table of our MySQL DB and do a delete of the records we want gone? Or is that going to mangle relationships and frag the whole thing? I looked through the archives, but was unable to find anything answering this question. Thanks, Randy