I need an email server setup on a machine running Ubuntu 12.04. Specifications:
1) The server has multiple static IPs
2) Every IP is bound to a domain.
3) Incoming mail should be stored in separate folder for separate domain.
4) Outgoing mail should use the interface/IP corresponding to the domain.
You must take care of all security features associate with mail server (noone should be able to send emails without authentication, configure firewall etc). For front-end, you should configure a free email client with all features working. Bid ONLY if you can do the above PERFECTLY.