outlook 2016 on Mac - "Mailbox already exists" error.

Anonymous
2016-10-06T05:13:04+00:00

Error "mailbox already exists (0.000 + 0.000 secs)" - and outlook loses connection to IMAP server (shows empty account).

Then, either through manual intervention (clicking on another account and then coming back), or sometimes it just does it by itself, it "rediscovers" my IMAP mailbox and works OK... Until next time (falls over every ?? 30 minutes or so).

Using outlook 2016 on Mac, V15.26.1. This also happened on previous version.

Didnt used to be a problem. Just started about 2 weeks ago with no changes from my end that I am aware of!?! Upgraded to latest Version today. Made no difference.

Advice welcome!

Outlook | MacOS | Legacy Outlook for Mac | For business

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  1. Anonymous
    2017-05-31T10:18:13+00:00

    I also have encountered the same issue with the frequent "Error "mailbox already exists (0.000 + 0.000 secs)" - and Outlook losing connection to the IMAP server (shows empty account).

    Then, either through manual intervention (clicking on another account and then coming back), or sometimes it just does it by itself, it "rediscovers" my IMAP mailbox and works OK... Until next time (falls over every ?? 30 minutes or so).

    Using outlook 2016 on Mac V15.34, MAC OS (10.12.5).

    I had to bite the bullet and purchase an OLM to MBOX converter and am now happily using Mac Mail.

    Very disappointed in Microsoft on their local of resolution to this.

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  2. Anonymous
    2016-12-27T14:29:53+00:00

    Same with me!  About 2 months both with my Macbook Air and my iMac.

    Reloads the IMAP inbox all day long and gives me the errors.

    I double-checked my settings and everything is ligit!

    I'm on 365 with 10.12.2 Sierra.

    Tried a new Outlook profile, tried regenerating the account, at my wit's end...

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  3. Anonymous
    2016-12-14T07:52:03+00:00

    I have the same problem for almost two months now...

    I have tried every thing but without success! even the support team of microsoft tried to take over my mac and figure out the problem without any results.

    I am now waiting to get any answers from them by calling every week for updates but their answer is always "We didn't get any answer form the mac department, we will call you tomorrow to with answers"..

    And I am waiting for this call for a week now.

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  4. Jim G 134.1K Reputation points MVP
    2016-11-01T16:02:17+00:00

    If I were troubleshooting this my next step would be in Outlook, toggle the Sync Status and Sync Errors window on by pressing Command-7 and then Command-8. Then just keep an eye on those windows for a while and see if any traffic going by looks problematic, especially when the problem occurs.

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  5. Anonymous
    2016-10-31T03:03:38+00:00

    Problem still persists. I have updated to all the latest versions of the OS and of the Office applications.

    Has anyone got a solution to this?

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