ETRN (abbreviation for English Extended turn) is an extension of smtp E-Mail minutes for Maildienste from nets, which are connected with the Internet not constantly by a dedicated line. It is defined in the RFC 1985.

During existing a choice connection an ETRN able E-Mail server is contacted for sending and receiving from E-Mail/s (- queues) by an inquiring E-Mail server. (Connecting expiration between E-Mail servers - not to confound with the clientseitigen connection establishment as with POP3.)

The ETRN instruction is an extension of the smtp turn instruction. The smtp turn instruction turns smtp a connection, so that the server delivers enamels over an existing connection. Unfortunately the SMTP TURN instruction had a large safety hole, for this reason the ETRN instruction was introduced.

Syntax

ETRN [<option character>] <node name><CR><LF>

The node name must be a FQDN, which corresponds to a CNAME or a MX pointer in the DNS.

Possible answers of the server

• 250 OK ONE, queuing for node <x> started
• 251 OK ONE, NO messages waiting for node <x>
• 252 OK ONE, pending messages for node <x> started
• 253 OK ONE, <n> pending messages for node <x> started
• 458 Unable tons of queues messages for node <x>
• 459 Node <x> emergency allowed: <reason>
• 500 syntax error
• 501 syntax error in parameter

Examples

• Server: 220 xyz.com ESMTP server
• Client: EHLO my.fqdn.com
• Server: 250 xyz.com
• Client: ETRN
• Server: 501 COMMANDs emergency accepted

...

• Client: ETRN myfqdn.com
• Server: 253 OK ONE, 3 pending messages for node myfqdn.com started

Related links

• RFC 1985 - The definition of ETRN (English)

Articles in category "ETRN"

We found here 7 articles.

Related Websites

We found here 6 related websites.

• ETRN - Wikipedia, the free encyclopedia
  The ETRN operation is useful for intermittently connected mail servers. See also ODMR. ... Retrieved from "http://en.wikipedia.org/wiki/ETRN" ...


• ETRN.com, Inc. :: Specializing in Secure and Flexible E-Mail
  ETRN.com is proudly using the services of The Spamhaus Project to ... ETRN.com is a leading global service provider of secure and flexible e-mail solutions. ...


• Postfix ETRN Howto
  As of version 1.0, Postfix has a fast ETRN implementation that does not require Postfix ... 220 my.server.tld ESMTP Postfix helo my.client.tld 250 Ok etrn ...


• What is ETRN
  The Gordano Messaging Suite provides a comprehensive cross platform set of messaging server products based entirely on industry and Internet Standards.


• What is ETRN - A Word Definition From the Webopedia Computer ...
  This page describes the term ETRN and lists other pages on the Web where you can find additional information.


• What's new in sendmail 8.8
  ETRN You can now request to flush the queue for your host. ... RFC 1985 describes the new ETRN command, which is a safer version of the old TURN command, ...