I have a client that constantly is hitting the 2 GB limit for OE folders (I'm doing what I can to change her habits or move her to something else). Recently, she went to delete items out of her "Sent Items" folder and compact it but got the following error:
"The folder is currently in use by Outlook Express or by another application"
The folder right now is 1.7 GB, so she's not over the limit yet. The last, most extensive, procedure I tried to get this to work was the following:
1 - Go into OE and set it to "Work Offline"
2 - Reboot into safe mode
3 - Start OE and, without touching anything in OE (while she's still sitting at the Welcome page and not in any folder), go to FILE > FOLDERS > COMPACT ALL FOLDERS
4 - Still fails once it gets to the "Sent Items" folder