re :I see that nicksasso21 may be having a similar issue (but with Office365), where you asked for the Access Error Code info,

In that error console information it said: mailnews.smtp: Command failed: 535 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant. Visit https://aka.ms/smtp_auth_disabled for more information.

The link mentioned in error console : https://aka.ms/smtp_auth_disabled That link goes to this location - I specifically include the info on 'enable smtp': https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/authenticated-client-smtp-submission#enable-smtp-auth-for-specific-mailboxes

The user discovered they were not enabled for SMTP. After switching it on - all now works. So I managed to help them sort out their issue.

Let's recheck your errors again In Error console. After clearing and restarting thunderbird then do a send - but create a new write message - do not use a message presaved in drafts - do not save in drafts. Then check error console - upload an image.

I have not been able to get Thunderbird to work with my outlook.com email address. W10/32 bit fully patched Thunderbird 128.2.3esr (32 bit) POP Mail Server outlook.office.365.com, port 995

• • my "user name" which is my email xxxx.outlook.com

SSl/TLS OAuth2

• • In SMTP Server**

outlook.office365.com 465 SSL"TLS OAuth2 xxxx@outlook.com

I should have mentioned that I DO NOT have an office365 account.

Logging to www.outlook.com with my UN (=outlook.com email address) and password works. Although the lack of a way to turn off the MS spam filtering makes it useless. I have put some MS thing on my phone and I think I had to do some 2FA thing at least once when bringing up www.outlook.com.

I should have included that I DO NOT have an office365 account.

Help please.

Sorry for the delayed response, had to deal with loss of power and other minor damage due to hurricane.

I restarted Thunderbird, captured the Mail and News Account, cleared error code console, sent new email, which failed and ask to retry, I retried and failed, then cancelled the email. Here is the output from the error code console, as an image.

Thanks.

EDIT: Installed Win 11 on another computer, installed Thunderbird v128.3.0esr, let it automatically assign IMAP and SMTP (using my hotmail.com email creds). It assigned SMTP with outlook.office365.com (587, STARTTLS, OAuth2). It will not send email neither. In the error code console (see third image), there is an extra line, right after the initial 535 error, stating:

"Error during AUTH XOAUTH2, sending empty response"

I deleted, uninstalled, removed profile, reinstalled Thunderbird, manually used smtp.office365.com (OAuth2 was listed) with same result. I repeated this and then tried smtp.outlook.com, but OAuth2 does not show up in the pulldown list (same as on Debian).

CSmith,

I have a related question and got the following response from David:

david

   Top 10 Contributor

10/2/24, 12:19 PM

the outgoing server should be smtp.office365.com, STARTTLS, port 587 Oauth2

I still can not received messages from outlook with TB but with the SMTP settings David suggested I can send email from TB. The whole story, so far, is in the question:

"Thunderbird fails to log into outlook.com now that 2FA is required"

by CCDman12

good luck

CCDman12,

Thanks for the suggestion, but as stated above, I already tried outlook.office365.com, smtp.office365.com and smtp-mail.outlook.com with no joy.

I checked out your thread and noticed you are using POP instead of IMAP, I use IMAP and I get my email but can't send. Have you tested using IMAP instead (outlook.office365.com, port 993, SSL/TLS, OAuth2)?

CSmith, I have a related question and got the following response from David: david Top 10 Contributor 10/2/24, 12:19 PM the outgoing server should be smtp.office365.com, STARTTLS, port 587 Oauth2 I still can not received messages from outlook with TB but with the SMTP settings David suggested I can send email from TB. The whole story, so far, is in the question: "Thunderbird fails to log into outlook.com now that 2FA is required" by CCDman12 good luck

now that 2FA is required....

You do not use F2A - you said in Thunderbird pop account are using 'Authentication Method : Oauth2' for both incoming and out. Assuming you have set up Settings correctly and have enabled cookies in Thunderbird, then you would get prompted to enter password - that is your normal password for your account and then you get another screen asking you to allow Thunderbird access to server by clicking on 'Accept'. If you have 2FA enabled then server gets confused because it's expecting you to a have created an app specific password, but when setting up Oauth2, it's expecting normal password and then it sets up an oauth token which is used by Thunderbird to access server.

But I'm curious to know how you got smtp to work - did you get asked for password ? Did you enter the 'normal password' and the clickon 'Accept' or did you enter the 'app specific password' ?

CSmith At this moment in time , vave you got 2FA enabled or not?

The server settings as per image look ok, but naturally, it does not confirm the User Name is correct. Talking only here about SMTP server settings - Username needs to be the full email address of the primary account. In Account Settings - select name of account and click on the 'Edit SMTP_server' button. Some people may have a hotmail email address and also that hotmail account allowed some additional/alias email addresses. But to send you might need to use the primary not the alias email address. Confirm email address is primary and it's the full correctly spelt no typos email address.

Then Check in stored passwords that the 'User name' is full email address with no typos eg: no commas instead of full stop/period and no hidden extra spaces. In stored passwords for hotmail user name - do you see two lines - oauth:// and also smtp://... ?