Currently, when you have blocked PMs, they are blocked for everyone, and if you want anyone to message you, you have to completely enable them in order to receive private messages.
What I am suggesting is the implementation of a command that lets user enable PMs from a specific user.
like /allowpm [id], then that user will get a notification that "[player X] is now accepting PMs", and then only the people who he has allowed PMs will be able to PM him. Use /allowpm [id] again to block PMs from that certain user.
