Posted on 2006-05-23
I have a question. We have the Symantec SMTP Gateway to filter spam and scan incoming/outgoing messages. Since we installed the new Gateway, we are unable to send messages to a few of our major clients with server too busy error. We contacted Symantec and they say there is nothing wrong with their software and that the other side is busy. We tried having Exchange sending messages directly to the Internet and that resolved the issue. The problem we have now is for SMTP Servers that do reverse lookup our messages is not coming from the IP that is in the MX record therefore reject the messages. The MX record is pointing to the Symantec Gateway.
My question is if I add an additional MX record and give it a higher priority, will the SMTP Servers that do reverse lookup allow the messages pass? I want to keep incoming messages going to the Symantec Gateway for filtering but want outgoing messages to go directly from Exchange.
Please provide links or examples showing that when the SMTP Servers do a reverse lookup it will look at all MX records entries.