Simple Mail Transfer Protocol

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Simple Mail Transfer Protocol

[¦sim·pəl ′māl ‚tranz·fər ‚prōd·ə‚kȯl]
(computer science)
An Internet standard for sending e-mail messages. Abbreviated SMTP.

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 fred@doc.ic.ac.uk VRFY postmaster

or expand a mailing list:

EXPN c-help

You can even send a message:

MAIL From:<fred@doc.ic.ac.uk> RCPT To:<fred@mailway.doc.ic.ac.uk> 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.
References in periodicals archive ?
In addition, the device now supports the ability to post energy reads on a scheduled basis using SMTP protocol.
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The product utilises the SMTP protocol and works in conjunction with the Windows 2000 SMTP service or an existing SMTP/POP3 server or Lotus Notes to deliver scalability, e-mail integration and ease of use.
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Through a powerful combination of IPS, virus blocking, anti-spam and embedded URL filtering technologies, Proventia Network Mail protects against spam and the full realm of malicious code affecting e-mail systems through the SMTP protocol, including phishing attacks, viruses, worms and other malcode.
It's nice that Microsoft recommends 'SMTP protocol inspection to filter out SMTP protocol extensions' as a workaround, but it's a simple fact that if you use an SMTP proxy in a firewall like WatchGuard's, you would not fall prey to this kind of attack at all.