unable to add the account.

When i check User Sign-ins(non interactive) Logs in Entra i am seeing these failures

Above the settings for one of my user

Dear Glenn,

As a forum moderator, I genuinely wish I could directly access your account or delve into the backend systems to diagnose and fix this for you. Unfortunately, my role here is limited to providing general guidance and solutions that can be applied by users. Since many users are affected at once, this is unlikely to be a local Keychain or profile issue on individual Macs. From my research, com.apple.accounts error 3 is a generic macOS Internet Accounts failure when the Exchange account setup cannot complete, and the usual culprits are EWS access, OAuth, Conditional Access, Autodiscover, or network inspection sitting in the path. Start with the organization and mailbox level settings:

Get-OrganizationConfig | Format-List EwsEnabled,OAuth2ClientProfileEnabled

Get-CASMailbox ******@contoso.com | Format-List EwsEnabled,EwsApplicationAccessPolicy,EwsAllowList,EwsBlockList

If EwsEnabled is explicitly False, find out which policy or security baseline set it before changing anything, as a recent baseline or hardening change would explain a simultaneous failure across users. Also check EwsApplicationAccessPolicy, since an allow list that does not include the macOS client would produce the same result.

Alongside that, it is worth reviewing:

1. Entra ID sign in logs for the affected users, including the failure reason and the client app shown
2. Conditional Access results, particularly any policy scoped to Exchange Web Services or unsupported clients
3. Exchange Online client access rules
4. Service health in the Microsoft 365 admin center
5. Autodiscover DNS and connectivity
6. Any VPN, proxy, SSL inspection, or content filter in the path

On a single test Mac, disable VPN and iCloud Private Relay, apply pending macOS updates, remove only the affected Exchange account from System Settings > Internet Accounts, restart, then re add it via Microsoft Exchange using automatic discovery and complete the sign in and MFA flow. Do not delete locally stored mail unless the mailbox contents are confirmed in Outlook on the web.

If the sign in logs show the requests reaching Entra ID and succeeding, the problem is almost certainly after authentication, which points back to EWS access or a network appliance rather than identity.

If the tenant side checks come back clean, a service request would be the next step. A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin.  

I truly hope you get your issue resolved swiftly. Please know that even though I can't directly intervene, directing you to the correct, specialized support is the most effective help I can provide from my position. Thank you for your patience and understanding. Please let me know if you need anything else. Wishing you all the best. 

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The "com.apple.accounts error 3" when attempting to add Microsoft Exchange accounts on macOS can occur for several reasons. Here are some potential causes and troubleshooting steps you can take:

Potential Causes

1. Network Issues: Problems with network connectivity can prevent successful account configuration.
2. Incorrect Credentials: Make sure users are entering the correct email address and password.
3. Firewall/Security Software: Overly restrictive firewall settings can block account setup.
4. macOS Version: Certain versions of macOS may have bugs affecting account setup.

Troubleshooting Steps

1. Check Internet Connection: Ensure that the Mac is connected to the internet and that there are no connectivity issues.
2. Verify Credentials: Have users double-check their email address and password for accuracy.
3. Update macOS: Ensure that the system is updated to the latest version of macOS. Sometimes, updating can resolve bugs.
4. Keychain Access: Open Keychain Access on the Mac and look for any stored credentials related to the Exchange account. Delete them and try adding the account again.
5. Check Security Settings: Review firewall settings or any security software that might interfere with the connection.
6. Remove and Re-add Accounts: If the account has previously been added (but not working), try removing it completely and then adding it again.
7. Use Microsoft's Autodiscover: If the organization uses Autodiscover, make sure it is set up correctly for Exchange accounts as it configures settings automatically.
8. Console Log: Check the Console app for any relevant error messages when trying to add the account, which could provide more insight into the issue.The "com.apple.accounts error 3" when attempting to add Microsoft Exchange accounts on macOS can occur for several reasons. Here are some potential causes and troubleshooting steps you can take:

   Potential Causes

   1. Network Issues: Problems with network connectivity can prevent successful account configuration.
      1. Incorrect Credentials: Make sure users are entering the correct email address and password.
         1. Firewall/Security Software: Overly restrictive firewall settings can block account setup.
            1. macOS Version: Certain versions of macOS may have bugs affecting account setup.

   Troubleshooting Steps

   1. Check Internet Connection: Ensure that the Mac is connected to the internet and that there are no connectivity issues.
   2. Verify Credentials: Have users double-check their email address and password for accuracy.
   3. Update macOS: Ensure that the system is updated to the latest version of macOS. Sometimes, updating can resolve bugs.
   4. Keychain Access: Open Keychain Access on the Mac and look for any stored credentials related to the Exchange account. Delete them and try adding the account again.
   5. Check Security Settings: Review firewall settings or any security software that might interfere with the connection.
   6. Remove and Re-add Accounts: If the account has previously been added (but not working), try removing it completely and then adding it again.
   7. Use Microsoft's Autodiscover: If the organization uses Autodiscover, make sure it is set up correctly for Exchange accounts as it configures settings automatically.
   8. Console Log: Check the Console app for any relevant error messages when trying to add the account, which could provide more insight into the issue.