Noxclient, xclient, xclientsasl, xclientrepeat, xclientsaslrepeat Channel Options

XCLIENT SMTP Extension Support
(New in 8.0.) The MTA&#x27;s SMTP server provides support for Postfix&#x27;s XCLIENT SMTP extension. The PostFix documentation for the extension can be found here: http://www.postfix.org/XCLIENT_README.html Use of XCLIENT is controlled by three main source channel keywords,,  , and  , and variants   and. is the default, and means that XCLIENT is not advertised in the response to EHLO and the XCLIENT command itself is disabled. If  is set, the XCLIENT command is enabled and the NAME, ADDR, PORT, PROTO, and HELO attributes may be used. enables the LOGIN attribute in addition to all the others. It should be noted that LOGIN specifies an external identity that must then be bound to the session identity through the use of SASL EXTERNAL.

By default, only one set of XCLIENT commands is allowed in a single SMTP session. Specifying  allows groups of XCLIENT commands to be repeated, allowing a proxy or similar agent to share a connection between multiple clients. allows multiple groups of XCLIENT commands including LOGIN. Note that care should be taken when these keywords are used since the server cannot determine the origin of a given XCLIENT command.

The primary visible effect of XCLIENT is on the contents of the Received: field the MTA adds. For example, if this XCLIENT command was executed: xclient name=foo.domain.com addr=1.2.3.4 helo=bar.domain.com port=12345 it would result in a header of the general form: Received: from bar.domain.com (foo.domain.com &#x5b;1.2.3.4&#x5d;) by server.domain.com (Oracle Communications Messaging Server 7.0.5.32    64bit (built Aug 18 2014)) with imapsubmit id &#x3c;01OJ9P51WPFC007KNZ@server.domain.com&#x3e; for user@domain.com; Mon, 20 Aug 2012 08:17:31 -0700 (PDT) However, the ADDR, PORT, DESTADDR, and DESTPORT attributes also change the contents of the transportinfo that appears in various mapping table probes, such as the probe to. Given the preceding XCLIENT command, the   part of the mapping probes would change to something like: TCP&#x7c;this-mta&#x27;s-ip&#x7c;25&#x7c;1.2.3.4&#x7c;12345 where note that the values to use in the "source IP" and "source port" fields have been specified via ADDR and PORT, respectively.

Note: Support for DESTADDR and DESTPORT was added in MS 8.0.2.3.

See also:
 * PORT_ACCESS mapping table
 * TCPIP channels
 * SMTP and LMTP protocol channel options
 * Channel options