Spam is sent mostly from forged addresses, so when you bounce the message it just gets sent on to the poor sucker who owns the mail address that was forged.
One of my domains was used as the 'from' address for a big spam run, and I would cheerfully strangle _everyone_ who bounces spam after recieving 90,000 or so returned mails that had not originated from my mail server in the first place.
Spam is sent mostly from forged addresses, so when you bounce the message it just gets sent on to the poor sucker who owns the mail address that was forged.
One of my domains was used as the 'from' address for a big spam run, and I would cheerfully strangle _everyone_ who bounces spam after recieving 90,000 or so returned mails that had not originated from my mail server in the first place.