Secondary Mail (MX) Server
Telstra Internet Direct provides a secondary mail server (secondary MX server) that can act as a back-up should your own primary mail server fail. The benefit of this option is that in the event that your primary mailhost (Mail Transfer Agent - MTA) is not available to receive email, the originator of the email has the option to send the mail to the secondary MX relay host, which will, in turn, continue to try to deliver the mail for up to 5 days.
In recent times, due to the large amount of spam and virus content in email, some customers have implemented filtering policy for certain offending sites on their own MTA gateways.
If you have such an implementation and also use the secondary MX system, you need to be aware that the originator may attempt delivery through the secondary MX relays, in which case the offending email may still get through the policy filters on your primary host. Accordingly, Telstra recommends that if you wish to filter sites at your primary MTAs that you should remove your secondary MX entries for your sites from the DNS to avoid the possibility of offending mail being relayed to your MTAs through the Telstra servers.
For more information or to configure our servers to act as a secondary server for your domain enter CustData (available to customers only).
