Failed to Receive Mail from A Client

[rardark]

Hello Everyone,

I have a client from Italy suddenly cannot send email to me and he receives a bound back immediately stating "550 5.1.1 invalid destination domain". However, I can receive mail sent from other clients. So is it the problem of his side? Thank you!

 

[xpy-xpy]

1. Rule out the possibility that the client has mistyped your domain name in the email address.

2. Use any online email address validity / reachability checker.

 

[rardark]

1. Rule out the possibility that the client has mistyped your domain name in the email address.

2. Use any online email address validity / reachability checker.

Thanks for the reply! He showed me the bounce mail and he typed the email address correctly.

I used Zerobounce for checking and below was the result:

 

[cPRex]

It would be best for him to get the full mail transaction log from his host to see if there are additional details there. If you don't see anything on your server for that message, the issue would be on his end. It sounds like a DNS lookup problem of some sort on the sender side, as the "invalid domain" portion of the error indicates a DNS lookup issue.