Outlook 2016 doesn't accept password or app password

I see a few responses as to potential mobile email clients that use OAuth, yet lots of chatter about business vs. personal, outook.com not allowing it, where allowed, not working (not all on this community; some in other online sources). Phew! Could they not help the end user and make this just a wee bit clearer. Egads!

I would hope MS would update this community that all is working (if it is). Yesterday, I was able to go about 14 hours without an authentication error, thinking "good, it's fixed" only to find out, oops, to premature.

I agree about accepting OAuth! It seems it's hard to find PC email clients that use Microsoft OAuth, except Window's built-in apps, which I don't personally like, especially for those with multiple accounts or running a business.

I *think* the new Mailbird 3.0 is finally using it for personal accounts. (They've always used it if you have a paid business email address through Microsoft.)

Mailbird is working for me so far today, too. But I'm not holding my breath until it lasts the entire day. I just checked Microsoft's official status page here Outlook and other apps are unable to connect to Outlook.com - Microsoft Support and there's nothing new, still says "investigating." So who knows??

All seems to be working well now, has since this morning. Outlook 2013, Thunderbird, and Lineage OS Android 8.1 mail app are all working on the first try!

I use Samsung Email and it recognizes Microsoft accounts as Exchange Accounts. I'm not sure it specifically asks for OAuth, but the server settings are definitely not IMAP. In fact, it won't even let me add it as an IMAP account for about a year now.

Outlook for Android, of course, uses Exchange for Microsoft accounts, personal or otherwise. I do believe you can add Microsoft email accounts as OAuth in Gmail for Android, too.

Nine Email works, too, and Aqua Mail (pro version) I'm pretty sure does as well.