Moderating PM's

[headlight]

I'm not sure if this is even the place to post this but here goes. I have several members attempting to lure folks away from my site and send them to a similar site. I'm looking for a way to moderate these PM's. I'm running vbulletin 3.8 and any help would be greatly appreciated.

[Swampfox]

If you know who they are, create a special usergroup for them and deny them access to the pm system.

also you could add the other site's domain name to your filtered words list.