It could be that Thunderbird is using OAuth to authenticate, not username and password. I would expect changing the password to cause the OAuth token kept by Thunderbird to be no longer valid, at least that's what happens with Google, but maybe Microsoft doesn't do that and the OAuth token kept by Thunderbird remains valid in this case (until it expires) after changing the password…

Hi,

Thanks for your explanation. That makes sense if Microsoft’s OAuth tokens remain valid even after a password change.

However, I want to ensure that whenever I change my email password, the accounts with the old password can no longer be used in Thunderbird, and it should prompt for a new login immediately. The reason I change my password is to enhance security, and I want to make sure that any previously used authentication is no longer valid.

Is there a way to configure Thunderbird (or Microsoft 365) so that changing the password forces a reauthentication in Thunderbird, requiring me to enter the new password? If so, how can I set this up?

Thanks!

If this was Google, you could deauthorise Thunderbird in your Google account, which would require you to repeat the Thunderbird authorisation process again using the new password this time. I suppose the same can be done in the case of Microsoft…