No PR - A Mail.app Rule
1. Get spammed by douchebag PR people
2. Create Mail.app rule that deletes any message containing the string "For Immediate Release" in the body (OR its attachments)
3. See slightly less of the spam you get from douchebag PR people
To test it on your own corpus, make a Smart Mailbox with this rule (and remember to include the Trash to see if it's working on recent crap)
I wish there were exposed actions to Bounce the mail, then follow up with a tactical nuclear device.