H B

Actually, it might not even be related to Duo, but to the redirect-uri. Nonetheless, I am not sure how I can eliminate the O365 landing page being the redirect-uri when the client-id used by the browser (which I copied into Davmail does not seem to support anything else...

Sorry for hijacking this thread, but I am experiencing my own difficulties with deploying Davmail with Duo... The issue I find is that after entering the 2FA credentials, the O365 portal appears immediately, instead of a blank screen with the code in the URL. The client-id I use is that which is used by the browser and the redirect-uri is the landingV2 one. (With other client-id values I had even less luck...)

Request for client_secret

Authentication window does not close

Median filtering

Yes, I witnessed the same effect. Thunderbird responds with "MODIFICATION_FAILED", and the event status keeps appearing as "cancelled" on the server, while Thunderbird keeps bouncing the error when attempting to remove it. My only remedy was to revert to v4.8.2, where this problem does not exist.