I solved this problem by deleting account from T'bird and then reinstalling which auto updated my server settings. But this was for outlook. com.

Hello RonSH! Many thanks for your advice. I'll certainly try it. Best wishes, Barry.

Hello RonSH! Many thanks for your advice. I'll certainly try it. Best wishes, Barry.

I would not recommend it.

You random request to re-authenticate will be Microsoft getting the jitters about you actually being you. Now it could be a time based thing, Microsoft are very coy about how often they are going to actually force this issue as there is no advertising revenue in you not logging into their web site.

There are however things that can possibly prompt more frequent re-authentication requests. 1. Use of a VPN. Providers get a little antsy when your phone is in Atlanta and your desktop is in Vientiane at the same time. This is a common side effect of using a VPN to mask you global location. 2. Using WiFI hotspots. Again this can be a frequent relocation of you. In my part of the world where Starlink is common in remote businesses, your location can move 2000km to the satellite ground station in seconds while you phone is still with you. 3. Antivirus products that use self signed encryption certificates, or are slow to respond causing frequent timeouts. These are mostly not supported in a system that uses a rather expensive to maintain chain of trust. 4. General "security" software that claims to protect you privacy by deleting cookies can also lead to issues. While they are not integral to the oauth process, they are used in saving the configuration in the re-authentication process.

Deleting and then reconnecting account access from Tbird is not an actual account deletion. How does this make Microsoft jittery? But as I said, my removal and reconnection was on the 'basic' outlook.com which I think they are renaming Outlook for Windows.

I perhaps should have used the word 'Removal' from Thunderbird rather than 'delete' though I don't think one can actually delete actual accounts via Tbird.

I also actioned same procedure on my lady's without issues. Obviously if one regularly took such action, I am guessing that Microsoft could become suspicious.

@RonSH

1. Removal of a pop account from Thunderbird will see the mail for that account disappear from Thunderbird. Not a good idea, or what most folk want to happen. Some very old POP accounts that used the global inbox by default, or later ones where the user expressly set Thunderbird to use the global inbox will be unaffected, as will POP accounts where the user had expressly set Thunderbird to leave mail on the server, as long as the server will automatically offer it on a new account will also be unaffected, but that isnot Google a major mail provider. If the POP mail account appeared in the folder pane as itself, then the mail will generally be gone.

2. In the case of an IMAP account the mail will also be deleted, but redownloaded. Not much of an issue, unless you have a lot of it and you start getting your mail over again 200 or 300 at a time. It might take a month for 100,000 or so email.

Deleting and then reconnecting account access from Tbird is not an actual account deletion. How does this make Microsoft jittery?

Never said it did. But from a support perspective it can lead to apparent data loss.

But as I said, my removal and reconnection was on the 'basic' outlook.com which I think they are renaming Outlook for Windows.

I simply don't care what Microsoft calls it. In my book, hotmail, live, MSN and outlook.com are all the same thing. An IMAP mail server on the internet with special "Microsoft" conditions because that mail server runs Microsoft Exchange server offering the"Microsoft implementation" of IMAP and POP mail protocols for getting mail, instead of a standards compliant server software. They just can not bring themselves to offer a standards compliant service.

This change they are telling everyone about. They are calling it "modern authentication" but it is oauth the same as has been used for Gmail and Yahoo among other for a number of years now but with added complexity. They can't be seen to be one of the last to adopt the technology, so they give it a Microsoft name and tell everyone it is new and modern. They also introduce "Microsoft Quirks" to the standard as their software is actually optimized to be internal corporate mail software, not internet mail software. See https://support.mozilla.org/en-US/kb/microsoft-oauth-authentication-and-thunderbird-202

To cope with the change you update the server names, restart Thunderbird and change the authentication method of oauth. Job done.

What I see this question about is the fact that oauth updates and authenticated automatically once the initial authentication is done until the provider says you must re-authenticate manually. It is this aspect I addressed in my initial reply.

I bow to your expertise ... the only reason I removed/reconnected Outlook was because other methods simply did not work - then. This solved our problems at the time, based upon some info I searched online ... from your comment it was obviously not a good search! Thanks for your clarification & apologies to Barry