Outlook 2016 doesn't accept password or app password

Good news here - partially.

My account was hit with this issue about two weeks ago, using gmail app on Android phone.

The problem still exists, even with app password. The good news is that a brand new account I created two days ago for cross checking, is now working on my phone like a charm.

I am afraid of deleting my standard account ;-) as I read about other users having trouble to set it up again on the same phone. I will try to get another Android phone to check if my standard account can be setup there too.

If you are using Outlook 2013, please check what version you are on (File, Office Account, About Outlook) . There are minimum required versions that got updated to work with two-step verification and app password, New minimum Outlook for Windows version requirements for Microsoft 365 - Microsoft Community Hub.

Outlook 2013 need to be at least at version 15.0.4971.1000. To make sure you don't get impacted again enable Windows to install the updates for you. Go to Settings, Windows Update, Advanced Options and enable Microsoft Update. This will ensure you have all the Outlook 2013 or 2016 updates.

My Mailbird problems are resolved from this issue, finally.

From not community member:

Since most mobile network have private Ipv4 (Same or some IPs shared by many devices), and may have public IPv6 ,but the same or some prefix among the devices may be treated as the same one by some service. The mobile network should behaves similarly alike the Home gateway WLAN.

Does the mobile network and WLAN have the same ISP or same dns? which may route to the similar range of ips of the MS server?

How about the wellknown public DNS such as google, cloudflare, quad9, and etc?

And suddenly wonder that if the Microsoft Exchange addin would be affected by the MS edge webveiw2? such as the DOH setting in the MS Edge.

https://learn.microsoft.com/en-us/office/dev/add-ins/concepts/browsers-used-by-office-web-add-ins

I just was able to set up my account again, but not as EAS but as EWS account, and only via mobile network, not via WLAN.

It seems that for some reasons some IPs got banned or blocked by microsoft for some time. Could be that it takes some time to get them unblocked again. I think this could be due to too much authentication failures from this IP...

This are only guesses from my side. At the moment, my connection works again when only in mobile network. Whenever I swich WLAN on I get the password prompt again with authentification failure.

I was able to set up the account via EWS with 2FA enabled and app password.

I will try to set it up again with EAS and in WLAN tomorrow or the day after