Outlook Express – Problem Compacting Email Folders

I received an email recently from a reader who was having problems with Outlook Express. As I have written several times recently, when you delete emails, they’re not really deleted — even if you "empty the deleted emails folder." Your email program still has the email in its data file — it has only marked the email as deleted.

The next time you compact the email folders, the folder would be rewritten without the deleted email.

Yury, though, was having difficulties compacting one of his email folders:


I can not compact my Sent folder. By the end of the compacting process I am getting an error message “The folder is currently in use by Outlook Express or another application”.

After closing the message the whole computer slows down, and some times I have to reboot it. I have an impression, that something is running in the background.

Also, lately when I am trying to back up my e-mail on the external drive, the process running continuously 2 or 3 times and volume is in gigabytes. It all indicates, that I have old unerased messages sitting somewhere in my computer.

As a result, I have problems sending e-mails. The e-mail seemingly does not leave Outbox, but in fact Outlook keeps continuously send it out, and the e-mail never shows-up in the Send folder. I had this problem before, and it always because there are to many unerased e-mails in my system.

Except before I was able easily to fix it by deleting and compacting files.

Please, advise. Thank you very much for your time and consideration.

Yury Ferkelman

I wrote back to Yury to tell him how to proceed:

First, let me comment that you wobbled back and forth between Outlook Express and Outlook in your message. These are two VERY different programs. Both do email, both are from Microsoft, and they both have the word Outlook as part of their name..

Your message header shows that you were using Outlook Express 6.0.

Try booting into Safe Mode, without networking. From there, start Outlook Express. Since you chose Safe Mode (without networking), Outlook Express won’t be able to try to send emails. Now, at that point, compact your email folders.

www.terryscomputertips.com/archives/news_20070826_2.php — includes Howto Boot Into Safe Mode


And, Yury wrote back to say that, by following this process, he was able to solve the problem.


  1. How this solves the “can not delete messages from Outlook Express” is beyond me. I get the compacting part, but what about the deleting part?

    • Outlook Express’ email file gets so big that OE can’t delete any longer. Compacting solves it.

      Since it’s still accepting new messages at that point, I would assume it is an intentional “warning.”

      OE will warn you multiple times that you need to compact its files, but many people just hit the Cancel button at that point. This may be a “final warning” before something bad starts to happen…



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