Quote:
Originally Posted by bhwong  Ideally, Zimbra should check the sender's domain and verify if this domain MX record match with the email server that it is coming from. But I suspect that Zimbra only check if the sender's domain match with the email server that it is coming from instead. |
There are many broken mail servers out there and using those checks is not likely to block real MX mail. For further information I'd suggest reading the relevant postfix documentation:
Postfix Configuration Parameters