name based routing
 

Is there a way to create a name based routing system. To expand on this say you have 1 public IP and 5 servers that need to be to be acessed from the internet. say client xyz wants the site site.com the server forwards the traffic to the ip serving the site. While user2 needs to ssh to server site2.com which is on a different server. I know the website portion can be done using virtual hosts in apache in conjunction with mod_proxy but how could it be done for other services? Anyone got any ideas on this one?

it can't. ssh and other network services like it have no concept of hostnames on the wire. you enter site2.com it does a dns resolution. from that point on the network level only references IP addresses and port numbers, nothing about the original hostname itself. you'd be looking at port multiplexing or an ssh gateway.

Do you know any free proxy software for pop and/or Imap? I have configured the postfix server to relay the mail to internal domains but don't know how to get it off unless it has direct access to the imap/pop server.

http://www.imapproxy.org/ among others. i think nginx might be useful too.