Outlook 2016 doesn't accept password or app password

Because that's the way I've done it for the last 20 years without a problem! I don't pretend to understand MS Exchange, but I don't believe it is relevant to me as I'm not running a business or MS Server.

This is an interesting (apparent) solution.

Is it still working for you?

Does the free Outlook app support multiple accounts?

I'm confused.

Why would you want to use an Outlook account as a POP3?

Office 2021 (Outlook 2021) supports modern authentication when configured as "Outlook.com/Exchange"

So why would you want to use POP3?

So, I use Office 2016, and of course Outlook 2016, which is not compatible with the new authorization rules. I have been struggling with this entire depreciation of older Outlook versions for a few months until Microsoft finally let us know what was happening.

I downloaded the "Outlook for Windows" App. It is eligible for the new authentication rules, and is free from the Microsoft store. It is certainly different, and does not seem to have all the features of Outlook 2016.

However, once I downloaded the "Outlook for Windows" app, and set up my outlook.com email in it, then the Outlook 2016 install settled right down. I am running both at the same time. My original thought is I would take some time to learn the new "Outlook for Windows" app, while still using my more familiar Outlook 2016 app.

So, to my surprise, so far at least, there have been no disconnects from authorization for my Outlook 2016 since installing and setting up the "Outlook for Windows" app. Not sure what is going on, but as the "Outlook for Windows" app authenticates my outlook.com email, the Outlook 2016 app flies under the radar. Maybe.

Anyway, I am letting the "Outlook for Windows" app just run in the background, and I am still happily using my Outlook 2016 app with no disconnects from authentication. For now, at least.

It doesn't matter if it's MSI or not. Only 2021 and later will support OAuth for the free MS email accounts.