Well, again, it's like the shoutbox and the posting limits. It never occurred to the people writing FORUM software that people would use it as their primary form of personal EMAIL. I would guess that with email, instant messaging, chat rooms, and such that they figured people didn't need to use the PM part of the system for heavy interactive communications, and that people who were actively exchanging dialog would move to a more convenient tool like exchanging email or IM. So, the only reason someone would be sending lots of PMs must be bad, and should therefore be stopped . . . hence the default limit of 5 PMs per hour. Which is actually a higher limit for allo than most people have. For members who haven't posted much, the limit is something like only 5 a DAY!!)
Which means I guess a little detail on how this software handles PMs might be helpful . . . .
First off, PM stands for "Personal Message" not private message. Anyone believing that the messages sent using this system are "private", please be advised!!! They are not. That's not to say they are as public as the posts, just not openly shared. Think of them like the Fantasy Board; hidden from most but easily read by those who know about it.
Second, everything in the forums is pretty much the same thing. It's one big common system. You post messages to topics on boards. The gallery is just photos as messages posted to albums as topics on member names as boards. The new mall and store fronts are just locked messages and the storefront is a topic, and the mall is just a board. Likewise, your PM are just another message and your inbox is just another board. Every PM ever sent is stored away in the database along with all the posts. Even when you delete a message from your inbox, it is still in the database. It's just not displayed for you. So every message you send is saved for posterity and takes up space and gets backed up to my personal hard drive every so often. So sending thousands of PMs may not show up in the post count, but it still bogs down the system, and really isn't what we want.
Third, the system does allow you to get an email when you get a PM. The system basically sends a copy of the PM to your registered email address, if you checked that option. BUT the ISP we're using limits the number of outgoing messages from the server. So, if people send lots of PMs to people who have opted in on the email notification, the outgoing email limit might be reached, and further emails would not get sent. So it is possible that I might not get a notification from the server about a problem or someone trying to notify an admin of an issue because too many PMs were sent earlier in the day. (This has never been an issue, and I doubt it will, but it could . . . the server limit is only 200 per day, so if several people were sending numerous PMs, it could be reached.)
So, with that said, has anyone other than all had a problem with the 5 PMs an hour limit? I can raise it if there is a real need.