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Can only receive, not send Office365

  • 3 replies
  • 1 has this problem
  • Last reply by xtrem123

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I added an new Office365 account into Thunderbird alongside my gmail. I have asked the organisation admin to enable 2FA/MFA.

Settings were automatically detected by Thunderbird and account added through MFA. Downloading of alla messages and folders were no problem.

But I'm unable to send email through the smtp-server (TB added smtp.office365.com). "Login with username xxxx failed" (it is correct username)

"Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'."

I've manually changed to smtp-mail.outlook.com as suggested by the KB from MS.

Tried with latest release of TB and latest beta (129b3), MacOS. Tried with clean new profile. Clearing passwords and cookies.

I added an new Office365 account into Thunderbird alongside my gmail. I have asked the organisation admin to enable 2FA/MFA. Settings were automatically detected by Thunderbird and account added through MFA. Downloading of alla messages and folders were no problem. But I'm unable to send email through the smtp-server (TB added smtp.office365.com). "Login with username xxxx failed" (it is correct username) "Unable to authenticate to Outgoing server (SMTP) smtp.office365.com. Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'." I've manually changed to smtp-mail.outlook.com as suggested by the KB from MS. Tried with latest release of TB and latest beta (129b3), MacOS. Tried with clean new profile. Clearing passwords and cookies.

All Replies (3)

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You might want to ensure your server is SMTP.office365.com and the authentication method is OAuth. Apparently that is the only authentication Microsoft will permit after the 16 September if all the posts using that date in this forum are to be believed. To use OAuth in Thunderbird with Microsoft mail site you have to use the server names office365.

There also has to be a Thunderbird restart between changing the server name and setting the authentication method to OAuth.

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Already aware of that and is in OP. TB detects all the "correct" settings.

Modified by xtrem123

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I added for fun my personal Outlook-account. TB identified everything and after MFA the personal account had no problem receiving AND sending. And after inspection it is the same settings as the Office365-account.

Feels like something is missing/blocked on the admin side of the organisation....

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