Have the mail admin check to ensure that Relaying messages has been shut off; this is the most common form of "e-mail hijacking" that gets done on the net. Another source of possible information would be the server logs. This is, of course, if they are using your mail server and not a spoofed one somewhere else. The e-mail headers can tell you some information, but anything plain text can be spoofed/forged and that makes tracking a little more difficult. As previously mentioned, make sure your mail admin sets the generic alias of *@annsartgallery.com to a mailbox other than your primary one. This way, anything that is sent to an invalid account will go there and responses from those e-mails will too. This will decrease the amount of backlash you get in your primary account. You may also want to setup an auto-responder for webmaster@ and postmaster@annsartgallery.com stating that you are currently trying to rid yourself of the spoofing attempts and invite people to send copies of the e-amils to a specific inbox for further investigation. As RH stated above, giving up your identity is a crap shoot if the cause is not found out. You could end up doing this hundreds of times if you do not find out how they are spoofing your domain name. If it was me, I would keep things the way they are and pursue trying to investigate as best you can. One thing that works to your benefit is that spam is so widespread that it gets deleted without much notice anymore. There are some people who still attempt to stop the spamming, but who is going to remember 100% of the domains they get spam from?