From SharePoint workflow no email going to one user

Question

Mailbox unavailable. The server response was: 5.1.1 <claire_chen@XX.com>... User unknown

Above is the user and above is the message from ULS logs.

It was confirmed from exchange and AD team that mail id is active. not sure what could be the problem.
From SharePoint I removed this user and added again, but no luck.
Also verified from CA user profile there are 2 different users with same display name but with different mail ids and employee ids. I hope this will not be a problem.

Please help how to take this further. Thank you

Answer 1

HI Wang,
Issue resolved, User does not have physical address in the LDAP, post adding it issue resolved.
Thank you for your inputs and support.

Answer 2

Hi @sns ,

Per my research, this error is more related to exchange server.

This means your exchange is not supported to send email directly to outside network.

Please try following steps to check and verify that there are no security or restrictions with these accounts that are causing the bounce and email error 550:

1. Open the Exchange management console.
2. Expand recipient configuration and click on mailbox or list.
3. Select the mailbox or list that is having the issue receiving the mail.
4. Click on Properties -> ‘Mail Flow Settings’ tab.
5. Click the ‘Message Delivery Restrictions’ and click properties.
6. Clear the check-box for ‘Require that all senders are authenticated’ and click OK.

More information for your reference:

https://bobcares.com/blog/how-to-fix-550-5-1-1-user-unknown-email-error-in-exchange/2/

https://blog.mailtrap.io/550-5-1-1-rejected-fix/

Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link.

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