Bulk emailings and bulk email companies are increasing at an alarmingly fast rate. One anti-spam technique that's almost completely ineffective is to ask the spammer to stop. For spam sent from on-line services and ISPs, it's often effective to send a copy of the spam, with full headers, to the abuse contact for the provider with a polite request to make them cut it out. Please take appropriate action to ensure this doesn't happen again. Some people will suggest tactics such as sending huge files to the spammer, but imagine how you would feel if the address you use was some innocent person's.
Spammers expect flames, presumably, and it is just like water off a duck's back.
It has the ability to filter all incoming mail, looking at the headers, subject line, or any text in the body. I do not have it transferred to the trash, because occassionally a legitimate message slips through. I check my spam folder once every few days to see if any legitimate messages slipped through. Analyze junk email to find appropriate addresses to send a prepared response to.