Outlook 2016 users with POP3 accounts that are downloading mail over and over or deleting it from the server when Outlook is set to leave it on the for a period of time, see Outlook 2016 POP Account Problems.
This problem affects Outlook 2010 users with multiple POP3 accounts delivered to one *pst file:
Outlook 2010 is downloading duplicate emails over and over again, but only for my additional accounts, not my default account. I have "Leave a copy of messages on the server" enabled and when I take this setting off, Outlook does not download duplicate emails and works correctly. However I need to leave mail on the server.
This is the result of delivering the secondary accounts to the default data file.
Background
When you leave mail on the server, Outlook needs to keep track of the messages it already downloaded. It uses a hidden message called Mailbox Manager, which it stores in the Inbox. In older versions of Outlook, each POP3 account had it's own Mailbox manager file. In Outlook 2010, the Mailbox manager file is stored in the delivery location for each folder. In Outlook 2010, only one Mailbox manager file exists in a pst when more than one account is delivered. Because one Mailbox Manager is shared between multiple accounts, the last message downloaded for the account is easily lost.
The Mailbox manager file in Outlook 2010 will have a name similar to this:
Outlook Message Manager () (KEY: 47656E6572616C204B657900)
This screenshot is from Outlook 2007, where two accounts are delivered to the same pst file.
kmrc says
Hi Diane, I have a similar issue with Outlook 2007 (12.0.6753.5000) SP3 MSO (12.0.6762.5000). I just started a month ago. I've always had the setting "Leave a copy of messages on the server" set along with "Remove from server when deleted from 'Deleted Items'". It starts receiving emails that are a couple of months old and older even after i've deleted them and emptied the "Deleted Items" folder. I've deleted the same emails now 5 different times and it doesn't matter. Also, this does not happen when i access my email via the web interface or on my mobile device. I never get the permanently deleted emails, just on Outlook. I have only one account and one PST file. Any suggestions would be most helpful. :)
Diane Poremsky says
>> Also, this does not happen when i access my email via the web interface or on my mobile device.
so the messages you deleted in outlook are gone from the server but outlook keeps downloading them?
If you mean that when you delete them online or from the device, the delete actually works... this usually means Outlook isn't properly talking to the server or the connection is interrupted before they are finished.
How frequently are you checking for new mail in outlook? Set it to no less than 5 minutes.
Dreamcaster51 says
I have a similar problem, as of today 19/01/2017 i have an old email from greetings123 telling me my account has been approved. I get the same email in my junk folder at least three times a day. Beleive me, that is frustrating. Unfortunately I am noot a computer geek so I find it hard to follow some of the advice here. Any ideas anyone, ??
same email, over and over & the same date so obviously it is coming from my computer or server.
Shailesh Ajane says
1000 of older msgs have been sending and receiving iam using outlook 2003 plz kindly reply for the solution
Diane Poremsky says
Are these messages saved on the server? Outlook wouldn't be sending old messages unless they are in the outbox but it will download messages saved on the server if the 'mailbox manager' file that tracks the last downloaded message is damaged or you create a new profile.
George says
My Outlook keeps downloading old emails. I thought I would let is run through the thousands of emails on the server and it would stop. But it then started all over again. My IP (Bell Canada) tried helping me by resetting some aspects of my account, but then they gave up and said I need to save my emails and folders and re-install Outlook. Is that going to solve my issue?
Diane Poremsky says
Sorry I missed this earlier. Reinstalling will not fix this problem. it was caused by a damaged mailbox manager file or you created a new profile or a new pst. if the connection to the server is interrupted, it will start over - not uncommon when there are a lot of messages.
You either need to let outlook download the mail (can use a rule for messages received within a certain date to filter the old mail), or delete it from the Inbox on the server - either by moving it to the deleted folder or to another folder.
See https://www.slipstick.com/general/outlook-downloads-duplicate-emails-from-pop3-account/ for more details.
Lidia says
Where exactly can I create another pst file on Outlook for Mac? I am running Outlook for Mac 2011
Diane Poremsky says
Outlook for mac doesn't use pst file. Do you need a new local storage file or a second local storage file?
Al Villota says
This is happening to me and I can't get it to stop. I am the smallest of small businesses and I can't afford not to be able to produce. Without my email functioning it is all but impossible. I am using an old version of outlook but I'm not sure which one.
Diane Poremsky says
What exactly is happening?
How many accounts are in your profile?
Look in Help, About or the File tab, About to get your Outlook version. It would really be helpful.
Steve says
Diane, is there a way to replace or reinstall the mailbox manager file? Every time I log on to Outlook, it downloads everything on my server, and I don't want to have to delete or move everything I have received before using Outlook, and my boss wants to leave our emails on the server, so I can't just change the option to remove them from the server...
Diane Poremsky says
No, it's a hidden file created by outlook. Is it repeatedly downloading everything? If it's just bring them down once, you can move the new duplicate items (using the last modified date) to a new pst then close the pst and delete it later. Once outlook has everything downloaded, it shouldn't download them again unless something is causing the file to corrupt.
George says
My outlook starts all over again after downloading 17,000+ emails! I have tried all your suggestions and have not been able to stop it!
Diane Poremsky says
See https://www.slipstick.com/general/outlook-downloads-duplicate-emails-from-pop3-account/ for suggestions.
Marvin says
Hi Diane. I hope you can help me with this. I have this colleague who is having problem with her outlook account. It keeps downloading previous messages even dated 2 to 3 years ago (like 5000 messages), and it is causing her to much hassle. She asked me to fix it on my end. She is overseas so i dont know if there's a way I can access her unit. Maybe through event viewer. But how will i fix it? What is the process to prevent this from occurring? Your help will be much appreciated. Thank you in advance.
Diane Poremsky says
There are different ways to fix it, depending on the cause. When you use POP3 and leave mail on the server, Outlook keeps track of the messages downloaded in a file called Mailbox Manager. If that file is deleted or get corrupted (usually by AV software or scanpst), Outlook will download mail again since it doesn't know what the last message was. The solution is to not leave mail on the server or don't leave it in the Inbox, as POP3 only checks the inbox. Either of these will definitely fix it. If your mail server config lets you archive older mail to a different folder, that would be the best & easiest solution. Otherwise you need to move the mail into a subfolder vor delete it.
Paul says
Found this today:
Edward Qu MSFT Support
Post
replied on 25/2/2014 9:01 PM
Hi All,
We have received some reports saying "Outlook and OWA users randomly receive blank emails with 'Outlook Message Manager' in the Subject" recently. Microsoft has been aware of this issue and is investigating it now. We are sorry for the inconvenience brought. The current workaround is to create a rule or filter conversation views. The rule should be created using "Subject" because the extra messages don't have Sender or Recipient details. We will update the status of the issue once we have any. Thanks for your patience and understanding.
Best Regards,
Edward Qu
Diane Poremsky says
Those are mailbox manager files that outlook uses to keep track of which message was downloaded and things like that. They are supposed to be a hidden message in the mailbox (properly known as Associated Content, if you use MFCMAPI to snoop in the Inbox).
larry says
Thanks Diane. It looks as though you were correct with the update
larry says
Hi Dianne
I have been using Outlook 2010 for the last 10 months or so and I have 4 mail boxes. The last couple of days it has been down loading mails that i have already downloaded.
I think I understand what you are saying about 1 Mailbox Manager, however I am not sure how to rectify this problem.
can you please assist.
Many thanks
Larry
Diane Poremsky says
I'm wondering if an update on Tues is causing problems... If the problem is caused by the updates, it should fix itself after re-downloading everything once. That is still a PITA.
Are they all using the same data file? Are the messages repeatedly downloading?
Irish says
Hi Diane, I have the same problem with Outlook 2007, everytime I hit Send/Receive, it will download all the stuff from my inbox in my webmail. I'm not sure what's happening...
Diane Poremsky says
Is Outlook set to leave mail on the server? What antivirus do you use? Some antivirus scanners will cause outlook to download mail over and over.
spenser says
hello
i have outlook 2003 and it seems to be having the same problem
it keeps downloaded old emails that i have already had stored in my inbox
it started once i set up my ipad to get emails from the same account
any idea what i can do?
Diane Poremsky says
Did you start leaving mail on the server when you added the ipad? Are you using itunes to sync it to Outlook?
Are you sharing the pst between two computers or profiles?
Outlook stores the number of the last message downloaded in the pst file and when the number is missing or corrupt, Outlook redownloads everything.
Tim says
I am having the same problem as well with Outlook 2003 but I have not recently added another device or user. Is there anything you can tell me on how to fix this problem?
Diane Poremsky says
There are a number of causes and unfortunately, there isn't a good way to avoid problems if you leave mail on the server. If the message manager file is messed up, it'll redownload everything on the server.
pav says
i have users with blackberrys that are getting this message. with only one acct why would they be getting these errors. Could it be that the blackbbery acct is reading the message while the client is trying to download the messages casing some kind of conflict
Diane Poremsky says
What type of email account is configured in Outlook and on the blackberry?
POP3 is prone to duplicates because the delete command (when used) is sent after batches of mail is downloaded. In older versions, its sent after the last message; in newer versions it's sent after every 10 messages (I might have the # wrong). If anything messes with the connection, outlook won't delete. When you leave mail on the server, it works the same way but with the Mailbox Manager file - if there is a problem and Outlook doesn't update the mailbox manager file with the last downloaded message id (or the file is corrupted), it will redownload the messages next time.
John C says
Hi, very good post. I've been struggling with this issue for weeks. Your post fits my situation almost a 100% but for the fact I am using outloko 2007 SP2. is it possible that SP2 introduced the Mail Box manager file schema you mentioned before? It is the only thing I can think of. As mentioned, This article decribes exaclty my issue. Please, let me know if I am right.....
best regards,
John.
Diane Poremsky says
I didn't think it did, but its possible an update changed 2007 to act like 2010.