I would like to see an option that alerts the Admin when a certain user sends over X amount of PMs. Otherwise you only catch spammers once someone alerts you about their doings.
It would also be great if the number of PMs a user can send (per hours) can be directly proportional to their total number of posts and/or registration date. This would also prevent freshly-registered spammers from sending out loads of PMs before being stopped.
