I've just upgraded my forums to 6.5.4 and have set a limit on the number of PMs users can keep in their box.
What I'm finding is that people who use the site most (my "core" users) have a lot of valuable information stored in their personal messages.
I need to keep the size of their mail boxes to a reasonable size, but at the same time, I don't want them to have to delete important correspondence. One of the users made what I thought was a pretty good suggestion: Allow users to email to content of a personal message to themselves. This way, they can keep the messages on their own machine as long as they want.
I noticed in the Version 7 PM management screen that there is a "delete selected" button for messages that have a checkbox. Couldn't we likewise have a button that reads "Email selected messages (to me)".
Lastly, couldn't users have an option in their profile that would have PMs emailed to them as well as kept on the forum?
I don't know about other boards, but at my site, Gunks.com, users have built up a large amount of quality infomration that I'd really like them to be able to keep. Having the info in your email box is about the best place I can think of.
Thanks.