Backup MX

[Mulligans]

Does anyone have a backup MX record solution they can share? I am essentially trying to setup a second relay or gateway server, to accept incoming messages when the primary server is down. It would be ideal if I could setup a whitelist on the server to forward all messages that match the whitelist directly into exchange, and anything else wait for the Primary server (in this case a Sonicwall) to be back up. I appreciate any advice.

-Bob

 

[wallst32]

Typically what I do is use a software solution spam/av filter, install on mulitple servers, set them up with the same policies and as redudant MX records, and have them forward to Exchange whatever mail is accepted. This way all incoming mail is treated the same rather than in case one FW up or case two FW is down. Most of these software products allow you to install on multiple servers at no added cost because you are licensed by user count.

In your case, w/o knowing the cost of another Sonicwall, my first suggestion would be to acquire another one. Rather than have a backup and primary, you can set the MX value to the same and in this case you can view them as load balancing (that's a better spin to the finance guys if you need to justify cost).

A low cost solution would be to install IIS SMTP as your backup MX (in this case you really want it to be a backup, so make it a lower priority MX). Have it queue the messages and forward them to the Sonicwall. Make exceptions for your whitelist to delivery to Exchange.

Keep in mind the rules you can set with IIS are very limited, so a step above that would be to use a spam/av filter software package.

 

[Mulligans]

Thanks, I am going to find out if I can have a second Sonicwall up and going. You mentioned IIS, where cna I put in exceptions for the direct exchange delivery? I did nto think that was possible.