Thunderbird IMAP responded: User is authenticated but not connected

Anonymous
2022-12-27T12:29:12+00:00

Since yesterday, my Thunderbird client cannot connect to the outlook.office365.com IMAP server and other users at my university are also having this problem. I have deleted the stored token and redone the connection procedure but it does not work. I get two error messages:

The current operation on 'inbox' did not succeed. The mail server for account ... (IMAP) responded: User is authenticated but not connected.

Server outlook.office365.com has disconnected. The server may have gone down or there may be a network problem.

This does not work on any platform: Windows, Linux or Macos. Via the browser, we can access the emails but it is a workaround because it does not support openPGP. We need Thunderbird

Outlook | Web | Outlook.com | Account management, security, and privacy

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Anonymous
2022-12-28T22:03:29+00:00

Hi Glenn,

Which version of Thunderbird are you using.

I have 102.6.1 which is the latest one. Can you try updating it if its not and then check.

Also under Thunderbird --> Click on the gear icon on the bottom left bar --> General --> Config Editor --> Show All

Type network.dns.dis in the search field

Select the very first option and click on the toggle arrow on the right, make it true

Close and reopen Thunderbird.. See if this helps

Let me know how it goes

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Anonymous
2022-12-28T21:34:14+00:00

Yes, it is worked for me too!

I just disabled ipv6 netwotking in thunderbird advanced configuration editor (network.dns.disableIPv6 = true)

and it is works again like a charm!

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  1. Anonymous
    2023-06-24T12:35:02+00:00

    There seems to be new issue. Everything was working fine for me until yesterday. Let's hope it's temporary thing....

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  2. Anonymous
    2023-01-05T07:20:07+00:00

    Can confirm the same here in a western european tenant, but still radio silence from Microsoft on my ticket.

    I hope that Microsoft can do a proper root cause analysis which also includes as to why they didn't communicate or acknowledge the issue so far. It looks like their support was overwhelmed and didn't get information what was going on. One key lesson I have learned myself is that most customers are much more forgiving about ongoing issues if there is communication that the issue is actually known and being worked on.

    Thanks to the engineers who have either identified and reverted the change that caused the regression or who implemented and shipped a bug fix.

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  3. Anonymous
    2022-12-29T09:27:23+00:00

    Thanks, that's worked for me. I suspected Microsoft as their changes have already caused us problems, and was very relieved to find that this too is of their making - and affecting many others across the world.

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