Good questions!
I've checked the settings and I don't see any default in place that will automatically delete all members' messages after a certain time has elapsed. I think this is something that is left to each member to decide whether they wish to enable it or not.
![Smiley :)](https://www.playmofriends.com/forum/Smileys/classic/smiley.gif)
You do have a maximum that you can store there at any one time - currently it's 50, including messages both sent and received. If you reach the maximum, you won't be able to receive any more (except from the admin
![Grin ;D](https://www.playmofriends.com/forum/Smileys/classic/grin.gif)
) until they're pruned back.
I was just trying the "Label" thing out to see what it does. It's quite nifty - you can create separate directories within your message area and move selected messages into it.
![Cool 8-)](https://www.playmofriends.com/forum/Smileys/classic/cool.gif)
And no, I don't believe there is currently an easy way to download messages in bulk using this version of SMF. Maybe it'll come up in a future release.
![Wink ;)](https://www.playmofriends.com/forum/Smileys/classic/wink.gif)