Recovering email after Disk Cleanup

A couple of friends of mine contacted me, telling me that they had run Disk Cleanup, after which all of their emails were gone. They were naturally a bit frightened, and I told them I’d see what I could do.
 
I found out that they are using Outlook Express, and told them to search for any *.dbx-files. They did so, and I told them to right-click on the file, choose properties and go to the “Advanced”-tab, where I instructed them to uncheck the “compressed” check-box, and click OK and Apply.
 
One thing to keep in mind, is to search for hidden files and folders. To do this, simply check the boxes as shown:
 

 
The resources I used to find the solution for this problem were as follows:
Undo “compress old files” in Disk Cleanup utility? (PCReview.co.uk Forums)
Outlook Express (Wikipedia)