Every time I close Outlook Express I get a notification which asks me if I want "TO FREE UP DISK SPACE, OUTLOOK EXPRESS CAN COMPACT MESSAGES". I do not want Outlook to do this. Is there a way I can prevent this notification from being presented at the end of each session? I have done a 'Help Index' search with various obvious words with no luck.
Outlook Express used to "compact messages in the background" but this behaviour was changed with the installation of SP2 (I think). That's why you don't see an option to untick the box in the Maintenance tab (see Gandalf's post).
The message you are getting appears every 100 times you close Outlook Express and presumably every time after that when you decline the prompt. I've hardly ever used OE so haven't seen this prompt but you might want to let it compact the messages on the basis that you won't be bothered by the prompt again until you've closed OE another 100 times.
The reason it doesn't compact in the background anymore is that corruption could occur to the files if the process was interrupted. So, on that basis, if you decide to let it compact the messages, don't start up any other programs at the same time.
The overriding reasons for allowing OE to compact files are:
To free up some HDD space
More importantly, when you delete files from OE, they don't actually delete but remain as .dbx files. The subsequent action of compacting does then finally delete those file and frees up the HDD space.
There is nothing 'sinister' about this process. ;-))