Question : Postfix Exchange 2003 integration

Dear all,
My existing infrastructure consists of Exchange 2003 (on SBS 2003) standalone. I am embarking on a project wherein I would like to use Postfix as a backup to the exchange 2003 server. How do I go about doing this?

All sorts of ideas are welcome.

Regards,

Einy

Answer : Postfix Exchange 2003 integration

exactly how are you wishing postfix to act as a backup?

Do you mean, if exchange goes down, that email gets routed to the postfix box and users retrieve email from there?  if so, good luck; seriously
even if you can get it to redirect delivery of email, postfix needs to have mail boxes for all the users and then you have to worry about reconfiguration of clients to go to the postfix server.  

now my guess is that you have your clients configured as exchange clients which means even if you make the ip on postfix to be the same as the exchange for when exchange goes down, you have a confliction in email retrieval methods (pop or imap).

Personally the way I'd do it is have postfix as a filtering server.  Basically setup spam and virus (at least virus anyway) filtering on the postfix server.  Have all email relay thru the postfix server and then to exchange.

In this scenario if Exchange goes down, email will be queued up on the postfix server and relayed once Exchange is back online.  If postfix goes down, you can add the IP of the postfix server to the exchange server and have email deliver directly.  I'm not positive how you'd do it, but I have to believe that you could even run a script that periodically pings the postfix server and if it detects its down auto add the IP as a secondary IP on its nic.  Then once you get postfix up again, you can manually remove it.

however i'm just guessing as to your setup and what setup I'll be having once I get exchange up and running at my company