550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain

Kevin 25 Reputation points
2023-07-11T00:13:15.3666667+00:00

I have an Exchange 2019 Server.

I had a client tell me today that when he sends me an email it is bounced back to him. He uses AOL.

I logged into my gmail account and send a test message to my exchange email. sure enough it was bounced back with the following error message:

Your message couldn't be delivered to myemail@mydomain.us because the remote server is misconfigured. See technical details below for more information.

The response from the remote server was: 550 5.7.54 SMTP; The response from the remote server was: 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain

I am able to send email with no issues to my gmail, outlook and yahoo accounts. The issue seems to be with just this account. In addition to the email address from the domain, it also has a second email address different from the domain.

For clarity. My Windows domain being mydomain.us, the first email address is user@mydomain.us, the second email is user@domaintwo.us. The user@mydomain.us,works, user@domaintwo.us does not.

All necessary DNS(MX and A) entries are correct.

I recently upgraded to Exchange 2019 and installed Exchange anti-spam features. I wonder if it could be related to that.

Anybody have an idea what the issue is and how I can fix it?

Exchange Server
Exchange Server
A family of Microsoft client/server messaging and collaboration software.
969 questions
0 comments No comments
{count} vote

Accepted answer
  1. Kael Yao-MSFT 36,751 Reputation points Microsoft Vendor
    2023-07-11T02:26:04.9033333+00:00

    Hi @Kevin,

    The user@mydomain.us,works, user@domaintwo.us does not.

    Do you mean if external senders send to user@domaintwo.us, they would get the NDR (error or bounce) message 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain.

    While if sending to user@mydomain.us, the email can be received correctly.

    If this is the case, what is the accepted domain setting on your Exchange server?

    01

    Please make sure you have the domain in the error message added as an accepted domain (Authoritative domain).


    If the above suggestion doesn't help with this issue, besides the accepted domains, please also post the following setting of the affected mailbox:

    01


    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.


0 additional answers

Sort by: Most helpful