Outlook 2016 doesn't accept password or app password

I do not know if it is fully fixed since there are sometimes hours without problems and sometimes only new password prompts and no authentification possible.

But you can try this:

Make sure that you have switched on two-factor authentication in the relevant account. If you already have, please also set up a new app password (if Nine does not support 2FA for microsoft accounts). Then try to newly set up your account (delete it first and then try a fresh set up).

Try to set it up as:

1. EAS with server outlook.office365.com
2. EWS with servers m.outlook.com and/or s.outlook.com

Try all this with both, WLAN enabled and disabled (so only mobile network)

It could be that this will fix your account since I guess that its not only a problem with their servers but also with some accounts or some account status on their servers.

BTW: For me since today morning all works fine with my account set up as EWS with 2FA on and App password. But I did not leave my WLAN for today, so it could be that I will still get errors later on. :-)

Edit: As I do not know Nine at all I do not know what this app/programm supports but after skimming the website, I think that at least one of the protocols mentioned above should be supported.

I have not received any emails or any other updates on Nine Folders since Jan 26th. Nine is an Outlook for Android. I tried to wade through the 37 pages of responses but couldn't find the answer. Is there a fix?

I am arriving the same conclusion of others and that you are not helping. You are one the asking if it's the same account and not just same password - it's really a silly question to start with. You have no senses why I answered the way I did... Please don't act like you are the only one can setup an email client and others on this thread somehow don't know what to do or don't have good understanding of technology. And no, I am not "hacking around" credentials. This is ALL your wild guesses because you do not have in-depth understanding of how and why people manages things certain way and they are also contradicting your own comments.

Every major platform try to gain access to monetize user data. The only difference is Google doing it with way more transparency than Microsoft. Google also respect user choices and Microsoft does not - this go beyond email/Outlook and go into the OS and Edge. Windows and Edge ignore and revert back user setting choices, especially around data gathering efforts. If I tell Google and Apple to stop, it actually stops, sync those settings across ALL my devices, and don't sneak behind my back and turn things on like Microsoft does, which is why I stay logged in on my phones and not so on my Window's devices. I can easily use a non-Play Store medium to download apps if I want to. This is also why I don't log into a Microsoft device with an account and it is really not your concerns either because it has nothing to do with this email issue. The situation is of Microsoft's email service and its interaction with Microsoft's own email clients. The issues and duration of the problem speaks volume. Outlook can operate regardless if the device is logged into a domain account or not. EAS protocol works regardless if the device is logged into an account or not... Much of your conjectures are nothing but wild guesses and invalid assumptions.

You're actually overcomplicating it. You don't have to use the account to log into windows, you don't have to log into edge. You just add the account under "email & accounts" in windows settings. You can then choose to use that account or not for various things. Outlook detects it automatically.

But for work, if you work for a large company, I don't understand how they would allow an offline/local account to authenticate you to company resources. So like I said, the authentication structure is flawed, if you do not want your MS account known to anything except outlook, then yes you're going to have to hack things a bit and your credentials will be lost from time to time after updates or every x days.

MS for better or for worse has moved to the ecosystem model, which is why they've made it so difficult to use an offline account in windows. As far as they're concerned, you should be using your MS account to log into windows which then will authenticate you to things like email, onedrive, optionally edge, and if your company is modern managed, your domain and resources as well. Apple and Google started the trend, MS jumped on board. Same with forced updates.

But then in the same message you say your phone is logged into your google account (which you don't really have a choice, not if you want to actually use most of the features of the phone) - so why no paranoia there? It is possible to use your phone without a google account, but it will be inconvenient and glitchy, exactly what you're seeing with MS.

You are over complicating things. One email address tie to one password, which is one and same account. We are not talking about aliases. The login email address is the account's email address. I also do not sign into the device with this account and computer's login account is a local account, so this is basically an email account being added to the email client. Same for both my work computer and personal computer. My phone is logged into a Google account for the device, so access Play Store and such. Only the email clients, GMail and Outlook for Android, are logged into these effected Microsoft accounts.

My practice is simple, I don't log into a MS account unless I have to, so my Edge browser is not logged into this MS account. I cannot imagine letting MS control even more aspects of my work and personal lives if they can't even work through this login/authentication issue.