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Office 365 account IMAP "Login to server outlook.office365.com failed."

  • 5 replies
  • 14 have this problem
  • 26 views
  • Last reply by eulaut

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Hi, until a few months ago I could synchronize my Office 365 account with Thunderbird on IMAP, however one day it stopped recognizing my password, and whenever Thunderbird tries to connect to the server it just shows a "Login to server outlook.office365.com failed." dialog.

I have also tried to set up the Thunderbird account in a clean environment in a virtual machine, but when I set up the connection configuration I get "Configuration could not be verified - is the username or password wrong?". I can connect to the Office 365 account normally through the web interface using the same username and password.

The autodetected configuration is: Incoming: IMAP, imap-mail.outlook.com SSL Outgoing: SMTP, smtp-mail.outlook.com, STARTTLS

I have also tried changing the SSL/authentication parameters in the manual settings, but to no avail, do you have an idea what happened?

Thank you

Hi, until a few months ago I could synchronize my Office 365 account with Thunderbird on IMAP, however one day it stopped recognizing my password, and whenever Thunderbird tries to connect to the server it just shows a "Login to server outlook.office365.com failed." dialog. I have also tried to set up the Thunderbird account in a clean environment in a virtual machine, but when I set up the connection configuration I get "Configuration could not be verified - is the username or password wrong?". I can connect to the Office 365 account normally through the web interface using the same username and password. The autodetected configuration is: Incoming: IMAP, imap-mail.outlook.com SSL Outgoing: SMTP, smtp-mail.outlook.com, STARTTLS I have also tried changing the SSL/authentication parameters in the manual settings, but to no avail, do you have an idea what happened? Thank you

All Replies (5)

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Are you using an App Password? If not, then you probably need to turn on two-step verification and then create an App Password to use in Thunderbird.

Hotmail/Outlook Mail: App passwords and two-step verification About two-step verification

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Separate from the 2-step verification option, note that the autodetected settings are incorrect:

https://support.mozilla.org/en-US/questions/1151035#answer-973918

https://support.mozilla.org/en-US/questions/1156972

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Thank you guys! sfhowes' answer was enough to get my old hotmail.com account working again.

However I have another Office 365 account which is used with my University's account credentials, and that still receives authentication errors on IMAP and even POP3, which I tried for curiosity.

I can't try Bruce's solution with this account because it doesn't login to microsoft.com, only outlook.office365.com, so what I've ended up doing is set it to forward the emails to my main mail account: not ideal, but it will have to do ^^

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Since I'm not a customer of "Outlook Office 365 for business", I cannot test for the correct settings. All I can do is refer you to their webpage for those settings:

POP and IMAP settings for Outlook Office 365 for business

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Thank you Bruce :) I tried those settings, they work for my old hotmail.com account, but unfortunately not for my University's Office 365 account. I will try to contact my Uni's IT support, and if they solve the problem and the answer is generic and can be of help to somebody else, I will post it here.