There is a little trick to the way POP3 email programs like Outlook, Outlook Express, Eudora and Thunderbird store the email messages you receive. A “deleted message” is not really deleted! Did you know that?
Outlook and Outlook Express store all the emails in one huge file, even if you have your emails split between multiple folders. Eudora creates a separate file for each email folder, such as Inbox, Outbox, Trash, Junk and any folders the user creates. Thunderbird similarly uses multiple files for emails.
The difficulty of both the one-big-file and the one-file-per-folder approaches is that computers take a significant amount of time to write large files. Huh? What’s that got to do with the subject?
As a result, when you delete an email or even a bunch of emails, all your email program does is to rewrite a few characters in the file in order to tell itself that a particular email has been “deleted.”
One particular marking in the file indicates that the email has been deleted, so the program shows it in the Trash folder. A different marking shows it has been deleted from the Trash folder. But, it really has not been removed from the big email storage files.
Each of these programs has a separate step available from its menus to Compact the file:
- In Eudora, it is under Special > Compact Mailboxes.
- In Thunderbird, the process is easy: File > Compact Folders.
- In Outlook Express, the process is almost as easy: File > Folder > Compact All Folders.
- In Outlook, the process is much more complicated to compact one of its .pst files. The process is: File > Data File Management, select a file, click Settings, then click Compact Now.
The "compact" step rewrites the file, eliminating all the dead space that was formerly taken up by deleted files, including deleted spam — and actually eliminates the messages you deleted. Unless you do this step occasionally, the email program’s data files just continue to grow and grow and grow…