Microsoft Outlook Express periodically compacts email to save space. You can perform a manual compaction process when required to keep the application functioning efficiently. The compacted emails for each folder are stored in a database file. You may have problems retrieving the compacted messages if the database file is damaged. Microsoft has updates available on its website to help you retrieve compacted mails in Outlook Express, and you can locate the database file in which the emails are stored or backup copies of the files. Assistance is available through Microsoft Help Line and chat support for those who have issues with using Outlook Express.
Restart Outlook Express. It should retrieve the compacted mails from the DBX file for that mail folder. For more assistance, contact Microsoft Help Line and the tech support executives will help you fix your problem.