[W/K] :: Simple Mail Transfer Protocol

  Simple Mail Transfer Protocol
       
           (SMTP) A protocol defined in STD 10, RFC
          821, used to transfer electronic mail between computers,
          usually over Ethernet.  It is a server to server protocol,
          so other protocols are used to access the messages.  The SMTP
          dialog usually happens in the background under the control of
          the message transfer agent, e.g. sendmail but it is
          possible to interact with an SMTP server using telnet to
          connect to the normal SMTP port, 25.  E.g.
       
          	telnet mhs-relay.ac.uk 25
       
          You should normally start by identifying the local host:
       
          	HELO wombat.doc.ic.ac.uk
       
          You can then issue commands to verify an address or expand an
          alias:
       
          	VRFY fred@doc.ic.ac.uk
          	VRFY postmaster
       
          or expand a mailing list:
       
          	EXPN c-help
       
          You can even send a message:
       
          	MAIL From:
          	RCPT To:
          	DATA
          	What is the point?
          	.
          	QUIT
       
          This is useful if you want to find out exactly what is
          happening to your message at a certain point.
       
          See also Post Office Protocol, RFC 822, sendmail.
       
          (1995-10-17)