Can no longer access my hotmail email account via IMAP

The only two ways I've been able to get email through this episode are:

1. With existing (and soon to be retired) IMAP settings (either server values), after each change of network state of the computer I slam the server with 10-20 or more consecutive send-receives across multiple email accounts, occasionally canceling all of those send-receives and repeating the process, and sometimes using a custom shortcut which runs a command to kill Outlook abruptly, then I restart Outlook and repeating the massive send and receive. Usually after a couple of minutes of that the IMAP counts connect and stay connected until the next time the network state is changed.
2. re configuring all email accounts for modern authentication by doing so from within Outlook 2021 professional (freestanding) and allowing Outlook to auto configure as exchange (which is different here than the exchange option is when run from the Windows Control Panel email applet).

I'm actually writing up some new details to add to an exiting thread here: https://answers.microsoft.com/en-us/outlook_com/forum/outlk_win-outtop_classic-outsub_ofh/authentication-failure-repeated-request-for/bc06f09c-e695-4655-b90b-481fd926db4f

There are Notes from my earlier testing at the link above. Since then I was able to configure properly working new email accounts (but not IMAP) in Microsoft Outlook 2021 Professional by doing the configuration from within Outlook and letting Outlook auto-detect the settings. NOTE: the auto-detect may behave differently from the Control Panel applet and use IMAP instead of modern exchange, and accounts configured via the exchange option in the Control Panel applet behaves as IMAP does rather than as the auto configured exchange from within Outlook.

Also, there are problems with Microsoft servers which have affected even their webmail interface and email accounts configured for modern authentication but those are are less frequent transient errors than the issues reported in this and similar threads. Although these authentication issues are less serious they do complicate the testing of the more serious issues. this might also be the source of this recent episode of IMAP issues.

Additionally, I think that whatever services or resources Microsoft uses to process IMAP while people switch to modern authentication seem to be failing or limited.

Adding to this mess is the fact that Microsoft's documentation regarding proper configuration for modern authentication falls short and the new method of configuring accounts which they expect defies best practices for workstation building.

More testing observations in the linked post above within a couple of days.

does not work

changed back to

imap-mail.outlook.com and is now working again

Win 10, Office 2021 Outlook (freestanding) > outlook.com and hotmail.com email accounts.

Interesting about server settings. In Jan 2024 when something similar occurred Microsoft allowed thousands of people to reconfigure email as if somehow all of these installations spontaneously messed up ... and then Microsoft acknowledged it was a back end issue and repaired the issue.

This time , for me started about a week ago with Outlook and Hotmail accounts. The existing accounts use the outlook.office365.com server as instructed by Microsoft, but attempts to configure new ones use imap.outlook.com or use exchange/ActiveSync settings at different attempts, and at different times the same credentials might be successful or fail.

Also, In both the previous instance from January and the instance which is occurring right now, "slamming" the server with many authentication requests sometimes forces the authentication to occur - eg 10 consecutive commands to send and receive all 7 email accounts results in some requests for passwords which then stop as the accounts finally log in. additionally as long as MS Outlook 2021 is running on the computer has not gone asleep on the network has remain connected there are no problems after having achieved proper authentication for all accounts

To your point, the imap.outlook.com server might be behaving better at the moment but also, on my PC after each time there is authentication of such a new account for then I am able to login again for a while with the long-standing accounts that use the outlook.office365.com server for that account. For that reason, in Outlook 2021 I have configured a separate Outlook profile where all accounts use the imap.outlook.com servers so the next time this occurs I can try that without manually re configuring accounts. I may also configure a 3rd profile with all accounts configured to exchange/ActiveSync.

None of this occurs with gmail accounts in same email applications, devices and network, nor does it occur in an android email app which properly handles modern authentication. The symptoms and behavior during both of these events seems to speak to the failure of back-end Microsoft services which allow IMAP accounts to connect with modern authentication specifically from Microsoft applications such as MS Office 2021.

Let's break that down: After a few years of forcing people to change server configurations for modern authentication and driving people to use Microsoft apps, Microsoft has created a situation where, from validly purchased MS software on validly purchased MS operating systems with properly configured accounts It is only the Microsoft products which fail.

Reading through this thread, I'm having similar, but not identical issues with the Outlook desktop client. I keep getting re-prompted for credentials on all of my IMAP email accounts. These are Hover mail accounts, and not Microsoft accounts. I have several exchange accounts in the same profile and they are not having the issue.

The various IMAP accounts prompt for the password. The password is already filled in. So I am just clicking OK for the response. Sending and receiving mail is working fine on all of the accounts. It's just that the prompts are driving me nuts. The frequency is highly variable, ranging from a couple times a day to every minute or two. It is also not consistently all IMAP accounts. Sometimes it will prompt for just 1 account several times in rapid succession, sometimes a couple accounts.

I do not have the issue on the IOS Outlook client.

Any help or suggestions would be greatly appreciated.

No indication of cause there or at the linked references but those are descriptions of what must be the same issue and it is good to see the reporting become consolidated and official. Still, MS is doing a poor job of sharing information to prevent people from changing credentials and server parameters. Thanks for sharing that link.

Also, there was a major Teams outage yesterday (affecting tens of thousands) which may have been a co-victim of the underlying issue with email, and an MS response quoted at CBS news describes a big cleanup involving "moving affected processes to backup systems" and "optimizing traffic patterns and applying configuration changes to reduce customer impact " which in itself could continue to disrupt service.

From: https://www.cbsnews.com/news/microsoft-teams-outages-block-limit-user-access/

This:

"In an X post on Friday, Microsoft 365 Status, the company's office account for service incidents, said it identified "a networking issue impacting a portion of the Teams service" and that it has moved the affected processes to a backup system.

The company added that it was making headway restoring Teams service in Europe and the Middle East. Microsoft also said it was working to protect its network in North and South America as it monitors the outages, adding that it was optimizing traffic patterns and applying configuration changes to reduce customer impact as quickly as possible. "

Thanks again.

Many thanks n0 hairs.

Fingers crossed that senior developers at MS are aware of this - looks like a serious bug.