Today I got a bunch of e-mail Undelivered Mail Returned to Sender messages.
It appears that some spammer abuses my pe7er.com domain name as from / reply address. They forge the e-mail from / reply address in the spam, so that it looks that the e-mail was sent from pe7er.com.
The SPAM is not send from my PC, not from my mail server (smtp.pe7er.com / ip address: 82.192.67.92), and not from my domain name.