If you are just receiving mail on your home box, and want to access it remotely with a terminal program, then you'd want to use something like "pine" (or any of the multitude of *nix mail clients).
The program would be configured like any other mail client: aim it at the ISPs mail server, tell it to retrieve your mail at some interval, and you're ready to go.
If you are looking to receive mail for a group / domain (that will use a mail client to retrieve it from your home system) then you'd be looking for something like "sendmail." In addition to that, you'd have to have your ISP register your system (in their DNS, mail system, etc) to forward any mail destined for your domain to your home system.
It's not a situation where you can just set up a server and the mail will come. The "Internet" needs to be told who and where you are.
If you use something like pine, then you won't have to open your firewall, because the session/mail requests are originating from inside. If you are trying to set up a server (for a group/domain), then you would need to open a hole through the firewall so the outside systems can forward the mail at whatever random time.
Make sure your parograms and patches area all up-to-date; a mess o' bad stuff is likely to be crawling in. The original viruses started with exploits in the mail system (sendmail) .... and after all these years, I still believe they haven't got it completely locked down.
Good Luck
Scott