Outlook Inbox not showing new emails using IMAP

• T

  Trevor

  2/27/26, 3:38 AM

  Hi,

  We've been using Mdaemon for a while now and we love it. We're still in the process of migrating email accounts from our previous mail server and we use IMAP. This is going mostly well with the odd quirk but we're defintely getting there!

  We have a mixed email client usage comprising of Thunderbird and Outlook and on one particular Outllok client we have an oddity where newly received emails do not show up in the clients inbox until either Outlook is restarted or a different folder has been selected and the inbox reselected. Even forcing a send and receive while in the inbox does not show the emails until either of the aforementions actions have been taken.

  I've tested the account on another instance of Outlook on another machine and it appears to work as expected and I've also tested it in Thunderbird and the Webclient and again both are fine which leads me to beleive it's somthing to do with the specific client installation. We have tried creating new profiles and even completely reinstalled Outlook but the problem remains. We are completely out of ideas as to why this happening hence reaching out on these formums.

  Is there anyting on the server end related to the account that could be causing this or can anyone point us in the right direction to help diagnose what's going on with Outlook?

  This is quite frustrating for the user as they are missing emails that are there becuase it's not displaying in the client until it's been restarted.

  Thanks in advance.

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• A

  Arron Admin Staff

  2/27/26, 6:45 AM

  I don't think this is caused by a setting on the server.  If it were, it would affect every client accessing the account.

  what version of Outlook are you using?

  In Outlook if you go to Send / Receive | Send/Receive Groups | Define Send/Receive Groups, make sure the box for Include this bgroup in send/receive and Schedule an autoamtic send/receive every X minutes are both enabled. 

  Then Select the Send/Receive Group and click edit.  Make sure Include selected account in this group is selected, along with Get folder unread count for subscribed folders, receive mail items, and download complete items including attachments for subscribed folders.  Then make sure all the desired folders are selected in the list.  

  Also check to make sure there are no other Outlook addins that are interfering. The best way to do that is to disable them.

  According to what I found online this could also be caused by a corrupted OST/PST file that persisted through a new profile being created.  To test this you'd need to delete the profile, and verify the data file for the account was also deleted. You can find the location of the data file by going to File | Account Settings | Account Settings | Data Files.

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  Arron Caruth

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• T

  Trevor

  2/27/26, 8:12 AM

  @Arron Thank you Aaron as always for some great pointers. I tend to agree it's more like the client end which is the problem and just thought I'd post here in case anyone else had experienced a similar issue. Googling turns up many of the suggestions you've made in various forms of which we've tried without success. I do think however if I could perform a true clean installation of Outlook hopefully the problem will go away! FYI we're running Outlook (classic) as part of the Office 2021 suite!

  Thanks again as always!

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• A

  Arron Admin Staff

  2/27/26, 9:04 AM

  Another option would be to take a look at the IMAP logs on the server and see if there are any clues about what Outlook is or is not doing that may help track it down.  You should see sessions for the IMAP client that SELECT INBOX and then at some point after that (before another folder is selected) it should send a FETCH command to retrieve message data.  Messages in the IMAP log are referenced by their UID values, so the easiest thing to do might be to look at the last session from the client and find the UIDNEXT value.  This "should" be the UID assigned to the next new message that is received.  Then send the user a message, verify Outlook does not show the user the message on its next send/receive, and then check the logs to see what Outlook has done with that UID.  Be aware that clients can Fetch an entire range of messages based on a UID value, so you need to be cautious about just searching for the UID value of the message.

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  Arron Caruth

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