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. NoOneCan 7,805 Reputation points Volunteer Moderator
    2022-12-28T11:22:02+00:00

    This issue is due to Microsoft having turned off Basic Authentication for POP3, IMAP4, Remote PowerShell, Exchange Web Services, Offline Address Book, MAPI, RPC and Exchange ActiveSync protocol in your tenant. You may ask your admin to check detailed information about these changes in Message Center via the Admin portal.

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  2. Anonymous
    2022-12-28T13:53:34+00:00

    same here. last successful fetch of any messages via imap was yesterday december 27 around 21:00 utc. also using thunderbird. also at a university. also accessing via outlook.office365.com using oauth2. have deleted the oauth entry in thunderbird's saved passwords and reauthenticated. have restarted thunderbird. have switched to basic auth and then back to oauth2 in case that would clear things. have tried using imap-mail.outlook.com instead with no joy. consistently getting this notification message from thunderbird:

    "The current command did not succeed. The mail server for account HWU responded: User is authenticated but not connected."

    followed by this notification message from thunderbird:

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

    i have no problem accessing my mail via firefox via https://outlook.office.com/mail/inbox.  as far as i know, i am using my correct primary mail address. i am unaware of any alias. outgoing email via smtp.office365.com using oauth2 works fine.

    where can i get more information about this?

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  3. Anonymous
    2022-12-28T16:44:25+00:00

    I am having the same issues. Are there any moderators who may be able to assist with this issue as it is still ongoing

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