The minimal mc file

Every .mc file must contain minimal information. This file defines the mail delivery mechanisms understood at this site, how to access them, how to forward email to remote mail systems, and a number of tuning parameters. The following table shows which items are required and also which items are recommended. It is recommended that the starting point for these items be as shown in the sample.mc file, and an investigation of all the m4 techniques that are available to customize the .mc file for your mail server is encouraged (see the bat book).

Table 1. Required and recommended m4 items
Item	Bat book reference	Required or recommended	Description
OSTYPE()	4.2.2.1	Required	Support for your operating system
MAILER()	4.2.2.2	Required	Necessary delivery agent
DOMAIN()	4.2.2.3	Recommended	Common domain wide information
FEATURE()	4.2.2.4	Recommended	Solutions to special needs
confBIND_OPTS	N/A	Recommended	Add for IPv6 errors on name servers

Example files can be found in the /usr/lpp/tcpip/samples/sendmail directory. The cf directory contains an example of an .mc file. Of special interest are the files that begin with generic. These files can serve as template statements in developing customized .mc files. The following example is a simple .mc file.

divert (-1)
divert(0) dnl
VERSIONID(`z/OS sample configuration 2002/09/20')
OSTYPE(zOS)dnl
DOMAIN(generic)dnl
MAILER(local)dnl
MAILER(smtp)dnl

The following information describes these common m4 items. For more information about these items, see the bat book.

divert

(-1) Ignore the following lines.
(0) Stop diverting and output immediately.

VERSIONID

Used to insert an identifier into each .mc and .m4 file that will become your header.

OSTYPE()

Support for operating system (the only ostype provided in the /usr/lpp/tcpip/samples/sendmail/ostype directory is zOS.m4).
Required.

MAILER()

Necessary delivery agent.
Required.
Known values include:
- fax
- local
- smtp
- uucp
- usenet

DOMAIN()

Common domain wide information.

FEATURE()

Solution to special needs.

RELAY_DOMAIN()

Defines hosts and domain names for which the sendmail server should allow mail to be relayed. By default, the sendmail server does not allow relayed mail. If the sendmail client uses the submit.cf file and uses FEATURE(`msp'), the sendmail server should be configured to allow this relayed mail.