Author: K.Kirkpatrick (2 May 05 10:50am)
The MX listing isn't on your server, it is in the DNS records for your registrar.
So, the mail isn't going through your server.
It is going to the Domain listed in your MX record...
The sending server says, "I have mail for... such-and-such DOM. Whats that address?"
The top level DNS server replys that the address to send that to is the IP address associated with the Domain you listed in your MX record.
It never gets sent to your domain, or your own IP... it goes from the sender to the honeypot mailserver.
You not only don't need to name the mail server for your subdomain... you don't need to host a mailserver for the subdomain.
Setting up a mailserver... and listing it in the MX record will interfer with the HP validation test.