Several of the original Mail User Agents (MUAs) for UNIX-like operating systems were originally written to allow the user to browse his mailbox on a particulair computer. This computer would be configured as the receiving SMTP mail server, and always running, to allow the emails to be delivered. For big sites, the system could be expanded by having the users mailbox mounted via NFS on a remote filesystem, thus allowing the mailbox to "exist" on any machine in the network, where the user logged in.
This concept is not exactly what is needed for the person who wants to install and run a UNIX-like operating system on his personal computer. In this case you will most likely have a POP3-account on one of your Internet proveder's servers. When someone writes you an email, it is sent to this server, where it is stored until you retrieve it to your local machine. This is often accomplished by an email program such as MS Outlook or Eudora. In the UNIX-world, Netscape Communicator and its offspring Mozilla have these options, but there is also a way of making everything work without using these programs. The solution is called Fetchmail.
Fetchmail is in fact a very small "glue"-program, used to retrieve your emails from the server, and deliver them locally. In this case "locally" means to the Mail Transfer Agent (MTA) running on your personal computer. The MTA will then deliver the messages to your local mailbox, and they can be read with any of the extremely many Mail User Agents (MAUs). Personally, I use mutt, which is an extremely powerfull text-based MUA. If you want more information, checkout my Mutt Configuration page.
As I mentioned, you will most likely be using POP3 to connect to your ISP's mail server, for retrieval of your emails. To configure this, create the file .fetchmailrc in your home directory:
poll mailserver.domain.org proto pop3 user username pass password nokeep forcecr
You should of course replace mailserver.domain.org with the name of your ISP's POP3 server. Username is your login on the server, and password is your password.
The nokeep-option tells fetchmail to delete the mail from the server after it has fetched it. Although the POP3 protocol will know which mails have already been retrieved, the server has to generate the list of emails each time you log in, which is extremely time consuming, so you will definitely not want to keep the messages on the server if you are using POP3.
After you create the file, make sure it is only readable by you, since it contains your password. This is done with:
chmod 600 .fetchmailrc
There are a lot of more complicated options for fetchmail, allowing it to use various types of authentication and encryption when communicating with the mail-server. This is no doubt a good idea, but is very dependant on the ISP's configuration of the server. The POP3 protocol is supported by almost any ISP, which is why I've used it in the above example. You should however consider if POP3 is secure enough for your wantings. POP3 will send your password in plaintext to the server, so anyone who has the ability to monitor the network traffic will be able to get your password. See the fetchmail (1) man page for more information.