Can no longer access my hotmail email account via IMAP

There does seem to be a new and ongoing issue with IMAP access to Outlook and Hotmail accounts which falsely presents symptoms of bad passwords or server configuration. I've been chasing this for three days (and managed to get a Microsoft ticket created but seemingly to no avail). Here are details:

Starting morning of Jan 24 2024: Frequent intermittent authentication failures for all IMAP Outlook (5) and Hotmail email (1) accounts in MS Office 2021 Pro Outlook on 2 Windows 10 Pro laptops and in email clients Fair Email and K9 Mail on 2 Android devices. All devices had been working fine for quite some time and experienced no recent changes or updates, and the problem persists after the application of latest updates.

• At each send-receive the issue occurs variably to one, some, or all of the accounts being processed. Email server reports "AUTHENTICATE failed".
• In Outlook 2021 after known good credentials fail, then at prompt to reenter credentials for said account, clicking OK to use the same credentials will eventually get successful login, but the number of repeated attempts required is variable.
• Issue occurs to different accounts at each send-receive, and each time it takes variable # of attempts before existing and unchanged credentials are accepted.
• Occurs with both variations of Outlook IMAP server parameters (outlook.office365.com/smtp-mail.outlook.com and imap.outlook.com/smtp.outlook.com) which both worked before this issue started. My default is outlook.office365.com/smtp-mail.outlook.com.
• Rapidly re-sending the credentials for an individual account is more effective than trying again later. In fact, in Outlook 2021 on PC once the process of repeating the credentials a few times for each account gains access then if there are continuous requests for send and receive (click send-receive many times to fill the queue and keep it running) they will all go through but as soon as there is a gap in the activity then the next send- receive may again erroneously fail to authenticate until the credentials are pushed through again. Lather rinse repeat.
• Occurs when configuring new accounts, which may or may not fail at first but then eventually get through.
• Occurs through different internet connections.
• Occurs with or without Antivirus, and with or without VPN.
• Concurrent log-ins not a factor (tested only one device at a time).
• Does not occur in any other email service provider accounts.
• None of this occurred before morning. of Jan 24.
• When one of the same accounts on configured as exchange on either PC (automatically or manually) it does not seem to have the same problem but I have only been testing that for a short while.
• In the Outlook Android app, Outlook and Hotmail email accounts are configured automatically as exchange with no option to configure manually or to review the server settings (which are offered for non-Outlook/Hotmail accounts), and the same accounts do not have the same problem in the Android Outlook app, which leads me to suspect it is using exchange.
• From early January 24 until early January 26 there were more reports about Outlook issues at Down Detector but at a low enough volume (40 complaints compared to a baseline of 5) that it does not register as an outage however later on Jan 26 the # of reports spiked to over 650 compared to baseline of 20. This particular information should be taken with a grain of salt but it's worth watching to see if it parallels the issue.

If this is some sudden new requirement to switch accounts to exchange accounts or otherwise reconfigure them, then the implementation and communication have been poorly handled but the aforementioned symptoms do seem to indicate some genuine IMAP problems at the server side. As it is, some people are changing passwords when there is no need and then just end up back in the teeth of the authentication beast. Additionally, just pounding the same set of credentials to eventually gets through might have the potential to cause accounts to be needlessly automatically locked.

For me, switching the Windows 10 PC MS Office 2021 Outlook installations to exchange would require work but might be viable and might not be a downgrade in functionality at the desk however switching from Fair Email on Android to Microsoft's minimally featured android Outlook app would be a big downgrade. Tomorrow I'm going to test on one of the PCs a separate email profile where all of the Outlook and Hotmail accounts are configured for exchange and see what happens.

Thanks to Karl who mentioned exchange. I was already curious about the fact my 2 PC Outlook 2021 installations chose different options (Exchange or IMAP) when automatically configuring accounts and although I've not figured out the reason for that, testing this issue in exchange was informative for this new issue.

As a FYI, this article from yesterday may be the cause

Outlook and other apps are unable to connect to Outlook.com https://support.microsoft.com/en-us/office/outlook-and-other-apps-are-unable-to-connect-to-outlook-com-f4202ebf-89c6-4a8a-bec3-3d60cf7deaef

Hello Dave R

Hi, I'm Karl and will be happy to help you today.

The correct settings for any Microsoft email accounts (@Outlook @Hotmail @Live @MSN) are as follows

*** as a FYI, all email properties use the same Outlook.com backend servers which is why you do not see a specific category for @hotmail

If you have any questions, don't hesitate to ask, we're here to help you further if needed.

There are a number of server names that are being phased out in favor of the standard ones that I included which have been in effect for quite a while

As for your screenshot - where is this from? More importantly, is there a reason you are using IMAP instead of Exchange (the default)? Am assuming this is because you're using a 3rd party email client that does not support the Exchange protocol

Have no idea as to why you can receive emails, but the Sent Items folder is asking you to log into the account. Something is missing from this description. Just to confirm, that isn't the server name you used for the SMPT server -- correct?

Hi Karl

I've set it up as shown in your screen capture.

Now I can receive emails and view my inbox.

However, when I try to open my Sent folder I get the following error message (I've redacted my hotmail email address):

Any ideas?

Also, do you when the IMAP server name changed? The old server name was still working yesterday - and any idea why users like me weren't informed of the change? Crazy that we should have to find out by posting in a newsgroup - don't Microsoft have access to email any more?

Dave