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Should I allow Outlook Express to compact messages, and how do I get it to stop asking me if I don't?


About 6 months ago I started getting a message (apparently from Outlook
Express, but even when OE is not running) saying “To free up disc space OE can
compact messages. This may take up to a few minutes. -OK/Cancel”. This has
become very invasive and, even after OKing (and losing use of the commuter for
several minutes), can pop up again within seconds/minutes and re-pop up within
seconds of being canceled. Cause and cure? I’ve deleted a lot of spam and
deleted messages in case these were the trigger.

My honest opinion?

Change email programs.

I’ll discuss that option, the bug that you’re seeing, and what you might do.
But first, I’m going to spend a couple of minutes explaining why I hold that


I don’t recommend or disrecommend products lightly. But what I will do is pay attention to the experiences of the users that post questions here on Ask Leo!.

Outlook Express is a fine, fine email program. Because it’s free and available on every copy of Windows XP, and came free with Internet Explorer prior to that, it’s a very popular email program.

“Unfortunately, more people report more problems and lost mail to me having used Outlook Express …”

Unfortunately, more people report more problems and lost mail to me having used Outlook Express than any other desktop email program, hands down. Next to losing all your email in a free email account, it’s probably my biggest source of email related data loss stories.

The most common culprit is, in fact, the very database compaction that you’re asking about. I’m sure it works well for many, if not most people, but when it fails it can be disastrous. Even backups can be problematic because Outlook Express is so touchy about the files and format of its email database.

And that, perhaps, is the underlying problem: Outlook Express uses a proprietary and apparently very touchy database format to store your emails. While there are third party utilities, often expensive ones at that, to recover, it’s simply not a particularly robust set up.

It’s hard to move, hard to recover, hard to repair and apparently easy to break.

But it’s free. Smile

The good news is that there are so many alternatives now, including free programs like Thunderbird that have almost everything Outlook Express does, that if it’s at all feasible I recommend jumping ship at the first sign of trouble. If not before.

With that out of my system…

I recommend you read this thread out on the Microsoft public discussion group. There you’ll find all sorts of recommendations that boil down to:

  • Compact regularly, or you may suffer database corruption.

  • If you’re up to date, OE will auto-compact after every 100 shut downs if you haven’t.

  • Never interfere with the compact process or you may suffer database corruption.

  • Don’t get too fancy in your folder organization or you may suffer database corruption.

  • Disable your anti-virus programs scanning of email and email files, or you may suffer database corruption.

  • Don’t let your folders get too big or you may suffer database corruption.

  • Backup, backup, backup in case you suffer database corruption.

As I said, for many, many people Outlook Express works, and works well. But in my experience fielding questions and hearing of problems, as soon as your own needs start to get more sophisticated in just about any way, it’s time to move on.

A note about Windows Mail – the Outlook Express replacement on Windows Vista – and Windows Live Mail – the Outlook Express replacement you can download free from Microsoft.

My feelings on these guys are mixed. They have both apparently abandoned the problematic data store format used by Outlook Express, which in my opinion is great news. It’s still proprietary, but hopefully more robust and recoverable.

However given that there are free alternatives with a stronger track record, if you’re considering a move I’d be much more tempted to move to these as more reliable “known quantities”.

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29 comments on “Should I allow Outlook Express to compact messages, and how do I get it to stop asking me if I don't?”

  1. OE stores emails in a text file – one per mailbox. That makes it a huge file but still readable through any text editor program independent of OE.

    The database is basically index that keeps tab on where each email begin among other information. This index often gets corrupted. But is recoverable. I have in the past just deleted the index file and OE would create a new more clean index.

    When you delete a message, OE marks the email in the big text file with a flag. but leaves it there till you compact the mailboxes. So a deleted message is still recoverable from the text file by just changing the flag back to the undeleted mail flag.

    The trade off for doing all this is that the files need to be reorganzed more often than with other programs. Thunderbird for example stores emails in “separate” text files and not one big text file.

    I would not suggest handling the OE files unless you know what you are doing. But then my suggestion is to take a backup of the OE mail folders. and then play around with the files. If things go from bad to worse, get the data back from the backup and you are no worse of than you started.

  2. Before reading Leo’s comment the first thing that came to me was, why not switch to Thunderbird. My reason also includes security. Many spam bots target the Outlook express mailing list. Of course the hackers may also hack into T-bird but I’ve heard of many more OE attacks. Another probem is that you can’t get rid of OE you can just stop using it. I don’t know it this still happens, but I deleted the OE directory once in win 98 to save space and it came back.

  3. Ah, but I started getting the annoying message about a month ago, and I don’t use Outlook or Outlook Express. Ever. At all. Yes, they’re installed as part of Windows XP, but that’s it. I’ve never opened either one. I finally Ok’d compacting the (nonexistent) messages and the prompt went away, but it’s a mystery to me.

  4. I too have many customers using OE and a few have complained it loses their emails during the compacting process. I have a greater issue with Tunderbird though. It has a nice user interface but once you’ve commited to Thunderbird, you better be happy with it. To export back to something else, especially Outlook, is an extreme hassle. Buyer Beware when going to Thunderbird!

  5. Yes, this is a very strange affair since, like the post by Cindy R., I do not even use OE, period. Yet the message to compact came up suddenly, without warning, asking me to compact the database. After saying “no” several times—and the message reappearing—I finally said “OK”, and the message never returned. Hmmmm.

  6. I’ve used OE for the past 12 years. I have tens of thousands of emails stored in many folders, several levels deep. To date I’ve had zero problems. I do compact the DB every so often, but have never had a problem. I do make regular backups, of course, but have never needed them. That’s not bad for a free program.

  7. Desktop search engines access OE several times a day; at 100 accesses OE sends the compact message. Get rid of it by going to Kelly’s Korner and downloading compactcheck.vbs. It resets the OE counter to zero.

  8. Outlook Express is tempramental, but like all wild animals it is easily handled if it is managed well.
    The key to a happy OE mailbox is not to store huge amount(hundreds) of emails in the default “Inbox” – create a new folder like ‘Keeps’ or ‘Archives’ or ‘Actioned’. On our 20+ network, the users that do use OE can have up to 2,000 emails in one folder. At this point is where OE starts to report “Unable to Display Message”. My guide is less than 1,000 messages per folder. The Mailstore is kept on a Network Storage rather than in the user’s Docs & Settings.
    One major important thing is to “Work Offline” when compacting mailboxes. If the compact process is interupted, there is a V.high chance of corruption. Go to File/’Work Offline’, then File/Folder/’Compact All Folders’ (after you have cleaned them up and organised them).
    If you really want to keep emails forever for archiving, there’s a great ‘free’ DBX viewer called OEView, that can read email messages from the database file as if they were in OE.
    For recovery, theres a good free extractor called DBXtract. I use both on XP.
    As with everything computer – it’s all about good management.

  9. When you get to many emails stored in OE it starts that wanting to compact.In other words when it reahes a certain number of emails.Once you compact it then waits till you reach that number again.Use gmail!!I run all of my email addys through my main gmail account,even my other gmail accounts.It is great.Takes care of all that junk stuff too.But also you can check junk folder when ever you want to make sure it doesnt have any good emails.
    If you are into OE stats then I reccomend ’email guardian’ by thundercloud.I use that to back it all up to my external drive and then clean it all out in OE and no more annoying message to compact.Then when I feel like making a stat or using a stat i can use oe.

  10. I use Outlook, which works ok. However, I still get the ‘Compact’ message from OE. Presueably this means it was installed at some point on my company laptop. If so, can I remove OE safely, without compromising Outlook? Cheers

  11. Re your advice here, in a nutshell are you saying that you should compact messages, but not if you are using O.E.?

    My advice is not to use OE at all. If you do use OE, advice from OE experts is, as listed above in the article, to compact regularly.

    – Leo

  12. Finally I get to disagree with you, Leo. Thunderbird, Eudora, Windows Mail, and Windows Live Mail all lack “Identities”, a most essential feature, although obviously Microsoft disagrees with me. No offense to them, but the folks that discontinued the Identities feature are programmers, engineers, and marketers, not business-oriented e-mail users. The Identities feature is too important for me to try to live without. Until Microsoft returns “Identities” to its e-mail program selections, I’ll stick with tried-and-true Outlook Express, because no way am I going to try to get by with an e-mail program about which the authors suggest that “users with different e-mail accounts log off Windows and log in as different users,” just to access different e-mail accounts. Even with a fast stripped-down operating system, that’s at least four minutes wasted. With Outlook Express, I can make the switch in seconds.

    Here’s a question: Does anyone know how can I get Outlook Express to work in Vista or Windows 7 without using my clunky solution of installing an older operating system in Windows’s Virtual OS?

    The only problems I ever, ever, ever had with Outlook Express were caused by me, not the program. Hint: Don’t ever neglect Leo’s admonitions about backing up your data!

  13. NOBODY seem to have answered or even addressed the second question – how do I get it to stop asking me ?
    Not even the MicroSoft thread whose URL is given.

  14. Edward Richter,

    For info about “Mail clients in Vista and Windows 7” go to which includes the following link to program for creating identities in Windows Mail: — go to its home page for other programs including DBXtract, which I have used successfully in the past when my OE was corrupted.

    If you really want to keep OE, perhaps you could go back to an earlier version of Internet Explorer, with which OE was bundled. (These are available at and and probably other locations as well.) There could be other problems with that, of course, including security ones. Perhaps Leo or someone more knowledgeable could comment on this idea, especially as I have no experience with Vista or Windows 7.

    (In fact, although I am typing this on my husband’s XP machine and I used XP at work for five years before retiring, on my own PC I am still using 98SE and of course the accompanying OE 5.5.)


  15. Josie, I went to Kellys Korner and spent a half hour looking for the download that you suggested for resetting the counter to zero. Where is it hiding??

  16. Ken Hall,

    See No. 367 in lefthand column at (found by Googling). I can understand how you could have spent half an hour or even MUCH longer trying to find it by simply looking around Kelly’s Korner. I tried using the Search facility at KK’s home page and got no results — found the answer by doing a Google search for “compactcheck.vbs”.

    Merna B.

  17. I read the question about the Outlook Express compaction message, which just lately I have been getting. I have NEVER used Outlook Express (just Outlook), and have never said “OK” to the message, just canceled out of it. How do I stop it from appearing?

  18. The first comment I see is Johnny’s, dated July 15, so I cannot find Josie’s note on how to get it to stop asking me dated July 14. How can I find it?

    Click on the link below that says “See all ## comments…”

    – Leo

  19. Windows Desktop Search (WDS) 4.0 (Windows Search)is causing this problem when it constantly searches OE. I understand that Nero can also cause this. WDS 4.0 was delivered in Windows Update a while back. The message even happens when you don’t use OE (Outlook Express). Uncheck the box in WDS that says to search OE. Then shut down everything you can, use a backup program such as and allow the compaction. OE compaction (IE7) will save big folders before compacting them, and they are later in your deleted items folder. I have the WDS problem. I have used Outlook Express for years, and have not had a problem in a long time. I have emails back to 1998 or earlier, and a huge inbox, plus 3 identities. I had a problem with Netscape in 1998, I believe it was, and OE was able to import in the mail when Netscape would not start. I also exported in everything at home when I left work. In OE, if you damage a folder, you can just put it back – each folde has a .DBX file. If you delete a folder, just add it back, and restore the original folder from a backup. The problem is that any time the OE folders are searched, the change date is altered since the folder is opened, and that causes incremental backups to be invoked by backup programs after a find is done in OE. (This might have been fixed in IE8, but I don’t know – OE ships with IE. WDS does a great job searching fast, but I am unchecking it for OE searching to stop this problem until it is fixed. There are other OE search programs, and I might try that. Good Luck! -J. Weinberg

  20. I found your site after searching for help. I just finished compacting my mssgs in OE, opened my email–my sent box completely empty, went to recycle bin, rt clicked on sent.bak, clicked restore, that disappeared and did not restore!! I can’t find it anywhere…very important info (and no, I haven’t been backing up my email files, which was a huge mistake that I won’t make again, but that doesn’t find my files now…). Yes, my windows updates are all up-to-date and I religously run my BitDefender virus and spyware scans. Thank you for any suggestions you may have.

  21. Hello Leo – Thanks for your helpful site! I went to Kelly’s Korner and downloaded compactcheck.vbs. My computer doesn’t know what program to use to install. Any ideas? Your discourse on Thunderbird has me interested and I think I’ll give it a try.

  22. In the original question, the writer asked “This has become very invasive and, even after OKing (and losing use of the commuter for several minutes), can pop up again within seconds/minutes and re-pop up within seconds of being canceled.” I don’t think Leo gets around to remarking on this issue at all: WHY, IN XPpro (and on my Dell Optiplex, but not on an earlier Systemax running XPpro), does this compacting option pop up so frequently (and surely not just after 100 shutdowns, as Leo says, and as MS evidently intended) ??

  23. Further to my comment above: The compacting option pops up frequently, often within minutes, even when it has NOT been canceled!

  24. if that option is’nt there,it may be on the outlook main page. it has been a while since i used oe. sorry if this did’nt help. they are supposed to have some fixes in feb.

  25. I never use Outlook Express. It is completely empty…no Sent or Inbox contents, no addresses, nothing. I don’t even have an OE address.

    But I still get the “compact” pop-up. There’s nothing to compact!
    Question is…Will clicking “OK” affect anything at all besides OE?
    And…Is there any reason not to just remove OE from the computer? Sometimes, at some web sites, you have to click on the words “email” to get to someone’s email address and that always brings up OE. I copy and paste the email address to my email provider and then cancel the OE page. Will I not be able to see those addresses if I remove OE?

  26. @John
    It appears that even though you don’t use Outlook Express, your computer has Outlook Express set as your default email program. If you go to “Add or remove programs” in the “Control panel” and then click on the “Add/remove Windows components” a list of components will appear. You can safely uninstall Outlook Express by clearing the check box to the left of “Outlook Express”.


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