I agree that it should be Admin only; and it'd be a great idea for there to be an option to be a 1 way notice or not... Last thing we need is to send a pm to the users group and have a spamathon... Mods however I think you'd value being able to send and receive.
I've always wanted to see some sort of way to:
1. Allow users to download an archive of their pm's, on a private topic basis.
2. Allow admins to troll pm's and purge them.
But, some have brought up that users keep important data in their pm's, so they should be able to flag something as important so the admin knows before deleting.
