Outlook 2016 doesn't accept password or app password

And why is this hit or miss (intermittent)? I can go for periods in a day, where it's working and then out of the blue, it's gone.

That's not surprising especially if there is a scramble to reroute resources, recover servers or otherwise triage the system. Previous references to the type of authentication and encryption and the fact that Microsoft is coincidentally(?) making changes to the Outlook ecosystem this month leave me concerned that this is a proprietary grab which Microsoft accidentally let out of the bag too early, wherein they plan to force people to use only proprietary products in which configurations cannot be changed or even reviewed as is the case with the Outlook android app.

And why is this hit or miss (intermittent)? I can go for periods in a day, where it's working and then out of the blue, it's gone.

I had App Password when the problem occurred. I was able to get to my account via Web login. So, the password is the right one. I suspected a problem with App Password and I disabled Double Factor Identification. With that move, I was able to access the account through Outlook 2016, but got asked for a password frequently. This happened intermittently, not at the frequency set for Send/Receive.

I then deleted the account in Outlook 2016, then reconnected. Imap was still intermittent. I received mail and the mail folders got synchronized. BUT, no synchronization for both calendar and address lists.

At this point, I am waiting for Microsoft to resolve their server problem.

Can you explain a bit more what you did? Did you do update to the new version of 9Folders? Did you delete the Outlook account from 9 and start anew? Deleting an account and starting anew is clearly a PITA, so just wanted to see if anyone tried this and was successful. Thanks

Personally, I tried this, and it won't let me add it back. Same with an app called Tasks. I get a "can't verify" error. May have to do what Nine folder article says, and basically delete and reinstall app and acts. Won't help my other apps though.