How do I retrieval Compact email

check in c:\\document and settings\*dir with your name\Local settings\Application Data\identities/ *dir with long name\Microsoft\outlook
there you will find your emails. Import from this place.

* = every one has different name on this dir.so you have to check what is the name of yours.

This is the solution from this site

Usually, when Outlook Express compacts email it just removes unused/empty space in the folder and the email stays intact but takes up less room. However, there seem to be a lot of people with the same issue.
Good luck.