On Thu, Apr 03, 2003 at 03:58:53PM -0600, Gerardo Gregory wrote:
A recent issue I encountered has prompted me to ask the following question. What I am looking for is clarification regarding the "proper" way of implementing Mail Exchange records, etc.
I have always been under the impression (or taught at least) that an MX record was necessary (required) for mail exchange. I at least believed that this was the correct way. Recently, we implemented a new mail server at our facility and started having some issues relaying mail to a few domains. Although this has already been resolved, I was under the impression that these two domains where the actual problem since I could not resolve an MX record for either one.
Since then I have learned that some MTA's will look for an A record if it cannot find an MX record and use the A record instead.
An MX record is good practice, but is not required or necessary. If an MX record exists, the MX record must be used; otherwise mail will be delivered to the host to which the A record points. -- The Pope has said this war is wrong, that it is a Sin. The Pope! But even worse, the Dixie Chicks have now come out against you! How bad does it have to get before you realize that you are an army of one on this war? - Michael Moore