Question
Our mail server is connected to two different networks via 2 different NICs – both paths to the server are over different IP ranges and both can be contacted via the Internet.
I would like GMS to act as a seondary MX record for itself so that in the event of one connection tot he Internet being unavailable the other would be used automatically.
Answer
In the situation where GMS is connected to two diverse network connections one can easily be set up to act as a secondary connection which would be used if the first were to become unavailable.
All that needs to be done is to ensure that the DNS records for the server contain 2 MX records, one of lower priority than the other.
The higher priority MX record should point to an A record which is in turn associated with the IP address of the main network connection.
The lower priority MX record should point to an A record which is in turn associated with the IP address of the standby network connection.
If you also want your users to access their mail over the standby network connection while the primary one is unavailable you shoudl also associate the relevant sendary IP addresses with the respective domains in GMS by adding the secondary IP address as an alias of the respective domain.
Those using the IP Connectivity options within the software will have to directly edit the options under Incoming > Connections to associated the IP’s with the domains.
Keywords:MX, Secondary, Backup