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 transport system, 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)