we have found a strange behavior of the domain: mydomain.com.
This domain receives all the email from the most important mail services but none from gmail.com
This email was sent by the server where it has been registered.
The mail system
<firstname.lastname@example.org>: Host or domain name not found. Name service error
for name=mydomain.com type=A: Host not found
If I send an email from gmail.com I get this error:
*DNS Error: Domain name not found
The strange thing is that the mail server receive correctly the email from other mail services like yahoo.com and other.