Email traffic redirect

Question

We have old email servers from our systems from years ago that are no longer around, in our application code are hard coded references to our old email servers. The code cannot be changed easily. Can I use dns service to redirect the traffic from those domain names to our new domain and email servers? Sorry to sound like a dummy , I am new to this.

Thanks!s

That should work, as long as the current mailservers will handle the incoming traffic as expected. — HBruijn, Jul 15 '14 at 19:31

score 1 · Answer 1 · answered Jul 15 '14 at 19:56

Yes, if the applications are hard-coded to connect by name, you can do something like:

emailserver    IN    A      192.168.0.5
oldserver1     IN    CNAME  emailserver
oldserver2     IN    CNAME  emailserver

and that way you keep one live emailserver name with one address (for ease of management in future), and redirect the old servers to point to it. Or you could do:

emailserver    IN    A      192.168.0.5
oldserver1     IN    A      192.168.0.5
oldserver2     IN    A      192.168.0.5

Which ought to work in the same way, but just means you have one IP address entered in lots of places, and makes it a bit less clear what the intent is.

If the applications are hard-coded to connect by IP address, you can't use DNS, but you could add the old server's IP addresses as secondary IP addresses on your live server, and make sure the email service and any firewall software accepts connections on those addresses as well.

The secondary IP address approach works only if the new servers are in the same IP network than old servers. — Tero Kilkanen, Jul 16 '14 at 02:31

Email traffic redirect

1 Answers1