I'd like to have a very lightweight and easy mail transfer agent on my server. The only purpose of this MTA is to buffer outgoing email messages locally and forward them to ISP's mail servers.

What options Ubuntu offers?

Criteria

• Easy to configure for forwarding purposes




• Simple - average user can understand how it works




• Secure - outside traffic is disabled




• No incoming email support needed

I have had various issues with sendmail and other complex solutions which are overkill for my modest needs.