Possible to restrict who can send PM based on post count?

[Chris Stewart]

I've been getting some spammers who are creating accounts, activating them, and then spamming users via PM. What's the best way to prevent this from happening?

[copiertalk]

create a user group from the registed members and upgrade them to the new usergroup upon x, Y or z post count.

[Chris Stewart]

Is that the only option? Is there a way to automatically change their user group upon post count increases?

[Lats]

Is that the only option? Is there a way to automatically change their user group upon post count increases?

Yes, usergroup promotions...
http://www.vbulletin.com/docs/html/usergroup_promotions