Simple Mail Transfer Protocol

messaging (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 [email protected]

VRFY postmaster

or expand a mailing list:

EXPN c-help

You can even send a message:

MAIL From:[email protected]

RCPT To:[email protected]

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)