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.
