app password required for outlook 2fA

[sbz1111]

When I try to access 2FA desktop Outlook accounts from Thunderbird, I am told:

You need an app password

We noticed that you tried to sign in with the password for your Microsoft account on one of these apps or devices. Since you've turned on two-step verification for sb**email address removed for privacy reasons, you need to use an app password instead for any of the following to work with two-step verification. We've sent this reminder to all the security info you've provided. If you haven't already done this, we'll help you set up these apps and devices with app passwords:

Outlook desktop app for your PC or Mac

I successfully generated an app password, but when I tried to directly access an Outlook account with it (not through Thunderbird), the password was rejected.  What am I doing wrong?

[#2 · Accepted solution]

You should not be using app passwords anymore, both Outlook and Thunderbird support 2FA for Microsoft (365) accounts. You can find detailed instructions on how to configure it for example here: https://support.microsoft.com/en-us/office/modern-authentication-methods-now-needed-to-continue-sync...

[#3]

@VasilMichev 

Thank you.  I have abandoned my attempt to use an APP password, as you suggested.

I have two Outlook accounts.  Let us call them:  email address removed for privacy reasons; email address removed for privacy reasons.  I can logon to both in Outlook using 2FA without problem.  When I try to access them in Thunderbird, after trying different settings, I can now also logon without problem, but with two peculiar behaviors:

1. Thunderbird does not require any password.

2. When I try to send a message, sometimes I have to change the SMTP setting from email address removed for privacy reasons to email address removed for privacy reasons or vice-versa.

I can live with this, but I wonder if I will eventually run into problems after Sept 16.  My current server settings are:

incoming:  IMAP, outlook.office365.com, email address removed for privacy reasons, SSL/TLS, OAuth2

outgoing:  smtp.office365.com, STARTTLS, OAuth2, email address removed for privacy reasons

and similarly for email address removed for privacy reasons.  Am I OK with this?  I have not yet dared to remove and re-install the Thunderbird accounts.

[#4]

@VasilMichev
Thank you. I have abandoned my attempt to use an APP password, as you suggested.

I have two Outlook accounts. Let us call them: a1 and a2 I can logon to both in Outlook using 2FA without problem. When I try to access them in Thunderbird, after trying different settings, I can now also logon without problem, but with two peculiar behaviors:
1. Thunderbird does not require any password.
2. When I try to send a message, sometimes I have to change the SMTP setting from a1 to a2 or vice-versa.

I can live with this, but I wonder if I will eventually run into problems after Sept 16. My current server settings are:
incoming: IMAP, outlook.office365.com, a1, SSL/TLS, OAuth2
outgoing: smtp.office365.com, STARTTLS, OAuth2, a1
and similarly for a2. Am I OK with this? I have not yet dared to remove and re-install the Thunderbird accounts.