Simple Mail Transfer Protocol

(redirected from SMTP protocol)

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. With this new technology, the meter can send this data out to a cloud-based software system for Internet of Things (IoT) applications.
Note that to have an exploitable Exim-based email server one has to configure extra security checks for the HELO and EHLO commands of the SMTP protocol.
Through a 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.
E-mail notification of incoming messaging via the SMTP protocol gives users the option to receive wave file attachments for voice messages and TIF attachments for fax messages.--AVST
The SMTP protocol, used for sending and receiving e-mail, has no built-in way to authenticate senders.
Source Authentication stays within the SMTP protocol and only requires that the sender reply to the e-mail.
"Combined with its current features which allow you to send mail using the standard SMTP protocol from any program that can use ActiveX/OLE components, ocxQmail version 3 is truly the premier mail component."
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.
The system recognizes, identifies and filters unsolicited mail messages when email is being received via SMTP protocol, hi this way, the filtering of spam is carried out before the message is delivered to the final recipients mailbox.
In order to send infected messages, the worm connects to a host machine by using SMTP protocol, and sends its copies to victim addresses.
The antivirus engine scans files of almost any format transferred via HTTP, HTTPS, FTP, POP3 and SMTP protocols. The files are scanned in real-time without noticeably delaying the exchange of information between users.
However, the operation of FTP, SMTP protocols and UDP based application protocols (namely DNS) is slightly questionable.