Might seem a bit dodgy, but like when your gone from the forums for like vacation or something, and don't come to the forums, for it to send you a email tellin ya that you've recieved a personal message from so and so and have the message in the email? But, have a option in user cp to turn it off..

no...

because you could easly visit http://shoutbox.menthix.net/private.php and they will be all there....

This is not like the reply notification in threads, where you can't otherwise know if someone replied in a thread you've subscribed to (unless you visit every single (and possible pruned) thread)

a bump from a very long time ago because I was gonna ask the same thing (I dun wanna make a repeat).

I would also want the same thing because sometimes I'm idle on MP!F and I dont change threads, so I would not get a pop-up until next refresh...and when i receive emails in my Yahoo! Inbox, I get a toast, so I can immediately go there.

does a 5 min/ one day delay matter?

I think this would be good if it did it when you weren't signed in (like if you are idle for too long) that way then it wouldn't always be annoying you whenever you got a new PM.  Just m opinion on it.