Manuel Dejonghe wrote:
> For the record: Any so called "agressive" spam filter replying or
> bouncing back the spam does in >95% of the cases not harm the spammers
> personally, but other spam victims.

That's why you should REJECT spam while it's sent to your SMTP server
and not discard it at a later stage. This is the only way spammers will
actually notice their spam got rejected.