Outlook 2016 doesn't accept password or app password

No PST file? So all your emails are either through EAS or IMAP and you don't delete emails from the server?

VBA is not supported on the "New Outlook" yet...MS' plan on merging Outlook desktop with New Outlook PWA is not transparent. Either way, "New Outlook" is a no-go for me.

I am working on the same... Did you have any large PST file and/or POP3 mailbox that you needed to import to Thunderbird? If so, how was the process? I hate installing or running unvetted process on my main computer and there are a lot of comments about that process doesn't go very smoothly.

Don't get Office/Outlook 2021 yet. First, I have the very latest through M365 subscription on my work computer, and I still have this issue. Second, Office/Outlook 2024 is supposed to come out soon and god knows MS is deprecating things left and right, so spending a lot of money now is not a wise move.

Longer term, you might start look for alternatives. Thunderbird is probably the best free option, but it can be glitchy if you are trying to import large PST files from Outlook initially. You might as well start now.... I don't think the current issue is purely Basic Auth versus OAuth because I should be using OAuth on the latest clients but still having issues. Ironically today, my Outlook 2013 only gave me one prompt, but Outlook for Android with OAuth has given me 114 prompts according to Android notification history. If the 2 MS people are to be believed that they will deprecate Basic Auth soon, then issues like this will only get worse. Give yourself time move things off Outlook.

Also, Proton Mail is coming out with a desktop client, so if you are concerned about privacy, it's another option. It's a decent option to have for those emails that you are willing to keep in the cloud and want to sync across multiple devices. They have calendar, drive, password manager.... so it is a decent one-stop option.

PST files?
I do not use those, those are a disaster just waiting to have a disaster.

I do on the other hand, make heavy use of VBA projects, and if a mail client cannot do those things, it is utterly useless.

Hi all,

The Outlook Team has updated the guidance about this issue, Outlook and other apps are unable to connect to Outlook.com when using Basic authentication - Microsoft Support.

A key take away is that everyone needs to work towards being on apps that support OAuth for Outlook.com. If you are using Outlook 2013 and Outlook 2016 an immediately available free option is to install the New Outlook, Outlook for Windows - Microsoft Apps. We will continue to update the guidance with learnings and status updates as we go.

Ok, now that makes it clear. I have an Outlook 2016 which is not supported (any longer). That wasn't clear in the beginning. I was using an app-password, which didn't really help. In-between, the issues on my iPad and iPhone didn't come up again, but still on Outlook 2016. Since I also can't (or don't want) afford the money for the 2021 Outlook, I have now changed with my various accounts (outlook.com, Gmail, iCloud and others) to Thunderbird and all is good again. I now erased Outlook from my PC. And while I was doing that, I also changed from Office 2016 to LibreOffice.

I perfectly understand that Microsoft moves to OAuth for more security, and I appreciate that. Maybe it should have communicated better beforehand, so we wouldn't have had a month of endless pop-ups for authorization. But I guess one can't always make it perfect.

For me, that pop-up-odyssey is finished (hopefully).

My phone also wont send