"What's goin' on?"
I've received quite a few messages from puzzled members who are frustrated that thier PM control panel shows their folders as 90%+ full although they've deleted most or all of the messages in their inbox.
The devil's in the details... Note that your panel doesn't read "Your Inbox..." is full, but rather, "Your folders..." are full.
By default, each member has two folders in their PM system: an Inbox and a Sent Items folder. And by default, each time you sent a new PM, a copy of that message is placed in your Sent Items folder unless you uncheck the box that does so.
What is generally the problem is that members don't realize they have more than one folder, and that Sent folder becomes clogged with copies of old sent messages, thus creating a situation where you may reach your quota and not be able to receive new PMs.
"So how do I fix it?"
Good question, and it's pretty simple. But if you are reading this it's probably because you haven't fully explored the PM control panel, so I'll walk you through it.
At the top of any forum page, click on Controls or My Controls, then from the options on the left, under Messenger, select My Inbox.
On the right side then, look for Jump to Folder, select Sent Items and click the Go button.
Now you'll see all of your stored copies of sent PMs. Select those you don't want or need to keep (usually all of them) and click the "Delete" button at the bottom of the page.
Ta-daa! Your folders are now have substantially more free space!