550 5.7.1 Command not allowed

Question

We are having issues with several things at the moment in Exchange 2013.  
One particular outside email address is returning the following code when replying to an email from within the organization:
<<< 550 5.7.1 Command not allowed 554 5.0.0 Service unavailable
The second issue is related as it pulls a similar code.  When one particular user sends an email from her account, or an attached account to a third specific account, she gets the following message:
Diagnostic code = SubmissionProhibited; Reason code = TransferFailed; Status code = 571
            < #5.7.1 smtp;550 5.7.1 Command not allowed>
No other user has issues sending to that account.
The third message happened once today, and is sporadic.  When another user emails a specific group, she gets returned with: Your message can't be delivered because delivery to this address
is restricted.
We've had some SMTP issues in the past where it would intermittently not send a message, but I don't know if its related, or how to fix it.  Any suggestions?

Answer 1

Hello,
If all these users are trying to send to a specific smtp, you need to contact their administrator to whitelist your domain/users. Some times, they need to add permission to receive external emails to their mailbox, distribution list etc.
Regards from ExchangeOnline.in|Windows Administrator Area | Skype:[email protected]