I need to configure smtp relaying on redhat enterprise linux server version 5.I have two servers with redhat installed at one location and other two servers installed at other location. At one location servers have public IP and at the other side servers have private IP . These servers are behind firewall.I have information about existing mail servers hosted on exchange.The servers with redhat installed on them should be able to relay mail to each other.Please let me know if I have to :
1) Configure sendmail on both the sides on one of these servers installed with redhat linux.
2) Can I use existing exhcange servers to relay mail between these servers.
3) Do I need to open the firewall port on both the sides for smtp relay based on source and destination.
If I can use existing exchange servers for relaying between these servers how do I set it up.
Machine installed with Redhat are configured with hearbeat configuration to have virtual IP.