Sun Java System Messaging Server 6.3 Administration Guide

13.3 To Configure the Native (/var/mail) Channel

An option file may be used to control various characteristics of the native channel. This native channel option file must be stored in the MTA configuration directory and named native_option (for example, msg-svr-base/config/native_option).

Option files consist of several lines. Each line contains the setting for one option. An option setting has the form:


The value may be either a string or an integer, depending on the option's requirements.

Table 13–2 Local Channel Options




(0 or 1; UNIX only) 

If FORCE_CONTENT_LENGTH=1, then the MTA adds a Content-length: header line to messages delivered to the native channel, and causes the channel not to use the “>From” syntax when “From” is at the beginning of the line. This makes local UNIX mail compatible with Sun’s newer mail tools, but potentially incompatible with other UNIX mail tools.


Specifies the location of the users’ .forward files. The string %u indicates that it is substituted in each user id. The string %h indicates that it is substituted in each user’s home directory. The default behavior, if this option is not explicitly specified, corresponds to:


REPEAT_COUNT (integer)
SLEEP_TIME (integer)

In case the user’s new mail file is locked by another process when the MTA tries to deliver the new mail, these options provide a way to control the number and frequency of retries the native channel program should attempt. If the file can not be opened after the number of retries specified, the messages remain in the native queue and the next run of the native channel attempts to deliver the new messages again. 

The REPEAT_COUNT option controls how many times the channel programs attempt to open the mail file before giving up. REPEAT_COUNT defaults to 30, (30 attempts).

The SLEEP_TIME option controls how many seconds the channel program waits between attempts. SLEEP_TIME defaults to 2 (two seconds between retries).


Controls the length of time in seconds the channel waits for a user’s shell command in a .forward to complete. Upon such time-outs, the message are returned to the original sender with an error message resembling “Time-out waiting for user’s shell command command to complete.” The default is 600 (10 minutes).

SHELL_TMPDIR (directory-specific)

Controls the location where the local channel creates its temporary files when delivering to a shell command. By default, such temporary files are created in users’ home directories. Using this option, the administrator may instead choose the temporary files to be created in another (single) directory. For example: