emacs has special modes for reading and sending mail. If you are using emacs from an X-windows session on an NCD explora, simply use the Tools menu to select Read Mail (with RMAIL) or Send Mail (with sendmail). The menu bar gets a Mail menu that provides various functions.
If you are using emacs through a shell connection such as telnet or ssh, so that the mouse doesn't work, you can use the keystroke combination M-x rmail to read your mail, and C-x m to send a mail message. Each of these modes has its own special key bindings: use C-h m to get a listing of them.