Sun Java System Messaging Server 6.3 Administration Guide

13.1 Predefined Channels

The table below lists some of the predefined channels.

Table 13–1 Predefined Channels




Used to specify which keywords are defaults for various channels. See 12.1 Configuring Channel Defaults.


UNIX only. Used to make routing decisions and for submitting mail using UNIX mail tools. 


Performs final delivery of mail to the local store. 


UNIX only. Delivers mail to /var/mail. (Note that Messaging Server does not support /var/mail access. User must use UNIX tools to access mail from the /var/mail store.)


Used to perform delivery via a site-supplied program or script. Commands executed by the pipe channel are controlled by the administrator via the imsimta program interface. 


These channels are used for deferred, offline message processing. The reprocess channel is normally invisible as a source or destination channel; the process channel is visible like other MTA channels.


Provides the means to reassemble MIME fragmented messages. 


Performs body-part-by-body-part conversions on messages flowing through the MTA. 


Used for messages that need to be discarded. 


Used to process messages for users who have been marked as inactive/deleted in the directory. Typically, bounces the message and returns custom bounce message to the sender of the message. 


Used to hold messages for users. For example, when a user is migrated from one mail server to another. 


Provides support for one-way email to an SMS gateway. 


Implements SMTP over TCP/IP. The multithreaded TCP SMTP channel includes a multithreaded SMTP server that runs under the control of the Dispatcher. Outgoing SMTP mail is processed by the channel program tcp_smtp_client, and runs as needed under the control of the Job Controller. 

tcp_local receives inbound messages from remote SMTP hosts. Depending on whether you use a smarthost/firewall configuration, either sends outbound messages directly to remote SMTP hosts or sends outbound messages to the smarthost/firewall system. Sometimes tcp_local gets mail from remote SMTP hosts via proxy or firewall. tcp_local is also sometimes used for internal relay activities.

tcp_intranet receives and sends messages within the intranet.

tcp_auth is used as a switch channel for tcp_local; authenticated users switch to the tcp_auth channel to avoid relay-blocking restrictions.

tcp_submit accepts message submissions—usually from user agents—on the reserved submission port 587 (see RFC 2476).

tcp_tas is a special channel used by sites doing Unified Messaging.