Experts (thank you in advance),
Our company recently purchased a new stand-alone spam filter. This device sits on the network, like any other system or server, receives incomming smtp traffic, filters the messages, and forwards any legitimate e-mails to the mail server for processing to the clients.
There are two ways to set this feature up. The first is MX Records (which we really don't want to do). The second, and preferred method is via Port Forwarding.
The external IP address for our mail server is NAT translated to our internal server (which happens to also be our web server). Therefore, we need to set it up so when an e-mail comes into this external IP address, it is NAT translated to the new spam filter's IP address, but all other traffic coming in (FTP, HTTP, etc.), needs to continue to be NAT translated to the web/e-mail server directly, without being forwarded throught the spam filter. How can I set this up?
Any help is greatly appreciated. I have included the part of my router config that I THINK I need to be looking at, please let me know if you need anything I'm not thinking of, or if I'm just completely off base with what I'm attempting to do. Thank you so much!
ip nat inside source route-map SDM_RMAP_1 pool NAT_Pool overload ip nat inside source static 10.10.10.100 216.x.x.x route-map rmap_1 (I don't wish to enter my actual external IP)
route-map rmap_1 permit 1 match ip address NAT_ACL_1
ip access-list extended NAT_ACL_1 permit ip host 10.10.10.100 any