I am guessing that you have done something I do myself; after being spammed, you decided to check out the domain from which the email seemed to have been sent.
Please let me assure you that my domain names (stetserfamily.com & saherk.com) were 'hijacked' from me several months ago. The really odd thing is that my gmail account gets the 'bounce-backs' and occasional answers/threats the spam engenders. The truly embarrassing thing is that, from the titles of the emails I see 'bounced back', at least some of them are sexual in nature.
I have tried to get help from the folks at gmail and my church's computer specialist, but apparently I have to wait for the spammers to grow tired.
In the meantime, I will never be able to use my own domain names for email again. since the spammers have succeeded in putting them on black lists of symantec and other anti-spam software.
My deepest apologies and I hope you will not be bothered by these hijackers again!
Captain PB Stetser