I run Spy Bot, Norton Anti Virus 2003, Zone Alarm and am fully updated and patched from all sources. Checks tell me that I am free of any infection and spyware etc However I am getting e-mails returned to me, that I have not sent, by servers as undeliverable. The e-mails are for prescription drugs.
I use a second party e-mail address, have the senders accessed my server ID?
... folks can clone email addresses - just as they spoof whole sites. It stops the anti-spammers from finding them, and shutting them down. Change ure poassword just in case, and report it to youe email supplier/isp.
I have had the same problem and my ISP (Claranet) does not want to know. Fortunately, I can't see that its causing any problems at present. My e-mail address is <myname>@<mygroup>.clara.net, and the highjacked part is @<mygroup>.clara.net with <myname> normally replaced by any random string of characters. Short of getting a new <mygroup>, there appears to be nothing you can do about it, and no-one seems to worry.