Outlook 2021 keeps prompting for login credentials

Richard DelGrosso 10

I upgraded from Office 2016 to Microsoft Office Home & Business 2021. I uninstalled 2016, then installed 2021. everything worked for a couple of weeks. Now, when I start outlook 2021, I get prompted for my login credentials for each of my hotmail and outlook accounts. (Enter yhour user name and password for the following server) Everything looks good, so I click "OK", but it fails to connect to the mail server. "reported error (0x800CCC92) email server rejected your login", "ERR Logon failure unknown user name or bad password". I can logon to the web mail with the same credentials without any problem - user name and password are accepted with out any problems. Is this related to the "modern auth" that just went into affect? The is the reason I bought 2021 was to alleviate this issue.

4 answers

Greg Rich 166 Reputation points

2024-10-02T00:52:51.9133333+00:00

Richard - I too am on 2021 and am experiencing the same issue which just recently arose. Same error code and same easy access to my email via Outlook.com using the same password. Very frustrating.
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ChristyZhang-MSFT 23,886 Reputation points Microsoft Vendor

2024-10-02T02:21:26.6833333+00:00

Hi @Richard DelGrosso ,

Welcome to our forum!

Looks like your case is related to this official article: Outlook and other apps are unable to connect to Outlook.com when using Basic authentication.

Outlook supports OAuth in all current Microsoft 365 subscription SKUs and Outlook 2021 LTSC (any SKU with build 11601.10000 or higher) when connecting directly as Outlook.com. If your Outlook is configured to connect to Outlook.com using POP or IMAP, OAuth is not supported. This means that when Basic authentication is fully deprecated, it will no longer connect. 

If it is your issue, please try the suggested options to use OAuth to connect your Outlook.com account in Outlook client.

Hope to help you!

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Richard DelGrosso 10 Reputation points

2024-10-02T05:08:19.53+00:00

Hi, Christy.

Thanks for your reply. However, I have already read that article and quite a few more. I chose to go with option #2. It is the reason that I purchased Microsoft Office Home & Business 2021. According to what I read on line, version 2021 supported OAuth, as well as POP/SMTP and ".pst" files. My current Outlook 2021 is "Version 2409 , Build 18025.20104, which exceeds the minimum build required as specified in the article you reference above. The reason I went with the desktop version of Outlook, is that I have over 20 years of both personal and work related ".pst" files that I need to be able to search through. According to Microsoft, support for ".pst" files in New Outlook and 365 is planned, but no delivery date is specified (possibly end of this year). So, 2021 was my only option.

Thanks,

Rich

ChristyZhang-MSFT 23,886 Reputation points Microsoft Vendor

2024-10-02T05:17:12.69+00:00

Hi @Richard DelGrosso ,

Thanks for your reply!

As i know:

Outlook supports Modern Authentication in all current Microsoft 365 subscription SKUs and Outlook 2021 LTSC (any SKU with build 11601.10000 or higher) when connecting directly as Outlook.com. If your Outlook is configured to connect to Outlook.com using POP or IMAP, Modern Authentication is not supported.

If you are configuring your Hotmail account as POP/IMAP, please try to create a new Outlook Desktop profile (Control Panel>Mail>Show Profiles>add) and then add your Outlook.com account using automatic account configuration.

More information: Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps.

Greg Rich 166 Reputation points

2024-10-02T12:06:16.0033333+00:00

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Greg Rich 166 Reputation points

2024-10-02T12:35:04.0166667+00:00

Christy - I too am experiencing the same issues as Rich. I am using Outlook 2021 Ver 2409, Build 18025-20104.

I am writing as I am confused by Rich's reply indicating he went with Option 2. I do not intend to install a fresh copy but wish to instead upgrade the security on my existing software. It seems that I need to create a new profile and then input my Outlook email address and Microsoft password.

Like Rich, my existing PST file houses years of communications which I wish to preserve. If I am on the right track and create a new profile, how do I link the existing PST to the new Profile.

Please let me know whether I am understanding your guideance correctly and how I should link the existing PST to the new profile.

Thanks for your help.

Richard DelGrosso 10 Reputation points

2024-10-02T15:18:11.4+00:00

Hi, Christy.

Thanks for the reply. However, I already read that article and many more. Since I have over 20 years of personal and business ".pst" files that I must be able to search and mine data from. I decided to go with option 2 listed above and purchased Microsoft Office Home & Business 2021. The main reason for doing this is because New Outlook and 365 do not support POP/SMTP and ".pst" files. At least not yet, maybe by the end of the year, but I could not find a specific time table. From what I read and what is stated in the support article you cite, 2021 does support OAuth, POP/SMTP and ".pst" files. But, now that I have upgraded, Outlook 2021 desktop client cannot authenticate with the Microsoft mail servers for hotmail.com and outlook.com. All of my other email accounts work, including Google email, AT&T email and Spectrum email. I am at a loss as to what to do next.

Thanks,

Rich

Richard DelGrosso 10 Reputation points

2024-10-02T21:03:33.4266667+00:00

Hi, Christy.

Sorry, this is a long one.

Ok, so now I am thoroughly confused. In the document you cite, one paragraph below the quote you show (Option 1 in this doc, Option 2 in the previously cited doc):

Option 1: Get a newer Outlook email app which supports Modern Authentication

If your Outlook client does not support Modern Authentication, you will need to upgrade to the latest version and then setup using Outlook.com Sync. You can either purchase a new Outlook License, use the Outlook that is included in your Microsoft 365 subscription, or download Outlook for Windows for free. 

Purchasing a new Outlook license is exactly what I did. Are you saying that my extremely old (Pre-Microsoft's purchase of Hotmail) hotmail.com addresses will work with 2021 OAUTH POP/SMTP and ".pst" files, but my newer outlook.com email addresses will not work?? Totally confused.

For both hotmail.com and outlook.com, I am using the same Microsoft mail servers:

POP3 incoming - outlook.office365.om, Port 995

SMTP Outgoing - smtp.office365.com, Port 587

Encrypted connection is - STARTTLS

If the client provides the user name/passwd and security required, how can the same servers distinguish between hotmail.com and outlook.com having OAUTH capability? That capability should come from the client, not the ".com" The servers should just receive the request, check credentials and if they are good, let you have access. You appear to be saying that your servers will accept OAUTH (POP/SMTP) for hotmail.com, but the outlook.com OAUTH (POP/SMTP) is not accepted. I'm afraid that I just don't understand this. If this is true, then I wasted $250 upgrading to 2021 for nothing. In order to get access to my ".pst" files, I will have to purchase third party software, go with a non-Microsoft client (i.e. Thunderbird) and/or convert all my ".pst" files to a new format even to get them into the New Outlook, plus uploading all of my email files to the MS cloud. This makes no sense to me. Oh, and by the way, I could still have access to my old ".pst" files if I could run 2 versions of Outlook on the same computer, but Microsoft doesn't allow that.

And, what does Outlook.com Sync get me? I don't care if I can read my email on my phone/ tablet or another computer. That is not my intent. I want copies of my email on my local computer. Paranoid, maybe a little. I have spent over 30 years as a Unix, Linux, Microsoft, Oracle systems administrator. I want my email local where I can control backups and storage. Unless something has changed, Microsoft does not guarantee that your email is secure and recoverable on its servers. Microsoft offers free email, it does not offer email security of any kind, nor is there any guarantee of any type of recovery in case of a catastrophe or accidental deletion of an email. On the other hand, I have multiple backup copies of my ".pst" files, in multiple physical locations. I can recover accidentally deleted emails to within a 24 hour time frame. If my house blows up, or my raid array gets stolen or destroyed, I can still restore my critical files without any worry.

So, how do I configure Outlook in Microsoft Office Home & Business 2021 to work as it should (and is stated in several MS articles, that 2021 will) with both hotmail.com, outlook.com, POP/SMTP and ".pst" files?

Regards, Rich

ChristyZhang-MSFT 23,886 Reputation points Microsoft Vendor

2024-10-04T07:26:15.0066667+00:00

Hi @Richard DelGrosso ,

Thanks for your reply!

According to your description, i understand that you cannot access the mailbox and want to continue to access the data in the PST file, considering that the issue is more related to authentication, we need to solve the pop-up window problem and it's related to server-side service, please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client. It's suggested that you could post your case in dedicated forum for Outlook.com for more professional advice.

Thanks for your kindly understanding and support!
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Mike Maier 0

To All/ Christy:

I too am experiencing the same problems outlined/described by all the folks on this thread. I have Outlook2021 (part of the Office Professional Plus 2021) showing Version 2409 Build 16.0.18025.20030 64-bit. I've attempted to use various combinations of the MS specified settings for POP/IMAP (noted in the included table below from MS) and still can not get either a POP nor IMAP connection.

I'm running on an HP WIndows11 Pro desktop and am using MS Office Pro... the specific details are:

User's image

I first attempted a POP or IMAP connection, which just left me in a perpetual loop of prompting me to change the username and/or the password.

I then went ahead (based on another MS recommendation) and allowed the autoconfigure using my outlook.com email account username. While that worked, and created the .OST local (on my desktop) file for Outlook 2021, it did NOT facilitate ANY POP or IMAP connections.

Thus, ALL the MS documentations that state that I CAN configure POP/IMAP connections are basically wrong/incorrect ????? I'm in the same boat as all the other folks on this thread.

Please advise! -mike

MAP server	outlook.office365.com
MAP server	outlook.office365.com
IMAP port	993
IMAP encryption	SSL/TLS
Authentication Method	OAuth2/Modern Auth
POP server name	outlook.office365.com
POP port	995
POP encryption	SSL/TLS
Authentication Method	OAuth2/Modern Auth
SMTP server name	smtp-mail.outlook.com
SMTP port	587
SMTP encryption	STARTTLS
Authentication Method	OAuth2/Modern Auth

Johnny Broe 306 Reputation points

2024-10-05T05:29:16.5466667+00:00

Resolution: should check the following registry key and value on your client and on the Exchange Server side: Registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa Registry value: LmCompatibilityLevel It's recommended to set it to a value of 5.

Explanation:

Send NTLMv2 response only. Refuse LM & NTLM Client devices use NTLMv2 authentication, and they use NTLMv2 session security if the server supports it. Domain controllers refuse to accept LM and NTLM authentication, and they'll accept only NTLMv2 authentication.
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Richard DelGrosso 10 Reputation points

2024-10-05T19:00:59.93+00:00

Hello, Johnny.

Thanks for the post. However, my registry does not include an LmCompatibilityLevel entry. Perhaps because I am not connecting to a business's Exchange server or domain controller. I (and I believe other posters here) are using MS office/Outlook on our personal computers. Thus, we are not necessarily connecting to an Exchange server, or Domain controller. In my case, I definitely am not. I/we are trying to connect directly to Microsoft's outlook.com and hotmail.com mail servers, without going through any intermediate Exchange servers or damain controllers. I don't think that the servers MS uses for these domains would be considered "Exchange" servers as understood in the private business context. While I could enter a new reg key and value, I cannot control what is set at the other end. Does MS set this value on their end? Please correct me if my assessment is incorrect.

Regards, Rich

Mike Maier 0 Reputation points

2024-10-06T03:52:21.86+00:00

Concur w/ Rich's last post and statements.....we are not using a corporate EXCHANGE account server. BTW I also do NOT have the specified RegEdit key in my Window11 Pro pc.

-mike

KEITH HARADA 0 Reputation points

2024-10-06T08:27:08.4133333+00:00

This all seems to be a systemic problem started on Oct 1 - about the same time I started to get errors on my Hotmail account in Outlook (v2021).

Johnny Broe 306 Reputation points

2024-10-06T16:05:56.76+00:00

I know that the problem in my answer is due to updating to CU14 on an Exchange server, so there were some client PCs that kept prompting for the password because the exchange of encryption went wrong.

It sounds like you have a similar problem for Microsoft 365 / outlook.com / hotmail.com

If inserting LmCompatibilityLevel doesn't help, you can delete it again :-)

On my own Windows 11, I have also installed the solution, see image:
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