Windows 10 Mail and Calendar app unable to sign in 365 online accounts

Luke Murray 16 Reputation points

I and my users are unable to sign in successfully to the Windows 10 Mail and Calendar apps.
We are in a domain environment and are using MFA. We do not have an on-prem Exchange, fully 365 with Hybrid AD.

Windows Version 21H1 19043.1052
Mail Version 16005.13426.20920.0

I have MFA bypassed my account during testing, information provided to app (user/pass) is accurate



The next display suggests everything has been configured correctly, however



You are then directed to re-complete the "Advanced" section of the original form. Which again fails.

As an additional measure, I have enabled "allow users to create apps passwords to sign in to non-browser apps"


However, the option is not available?


I have uninstalled (via PowerShell) the mail and calendar app. Re-installed and updated (via Windows store suggests, latest version)

I'm struggling to figure this one out and would like to have further understanding of the issue.

Windows 10
Windows 10
A Microsoft operating system that runs on personal computers and tablets.
10,598 questions
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1 answer

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  1. Yuhan Deng 3,761 Reputation points Microsoft Vendor

    Hi Luke,
    Based on my understanding this issue seems related to sync in these apps.
    I did some research and found this:
    Please try and see if it works.
    Also a few days ago, I had the same problem with my edge. To resolve it, I deleted all the cache files in IE and Edge, and finally the issue got fixed. I‘m not very sure about this one but maybe you can try it if you want.

    Thanks for your time.
    Best regards,


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