My domain is being used for spamming

photo credit: YandleI woke up this morning to about a hundred out-of-office replys in my inbox and junk mail folder.  It turns out, someone is using my Overpass.co.uk domain in an email reply-to and sending out loads of sex-related spam. I've been searching for what to do about this, and it turns out that there's not much I can do.  Since the spammers are not sending from my server and only using the reply-to, all I can do is hope that it stops soon. Apprently, this is a pretty common problem. If you get an email from Overpass, it wasn't sent by me.