Sendmail Operation Guide

Configuration files

sendmail(1M) cannot operate without a configuration file, which 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. This file is detailed in ``The configuration file''.

sendmail configuration can be daunting at first. The distribution includes an configuration package based on m4(1) that hides a lot of the complexity.

Note that text-based host files have been officially eliminated, obviating the need to hide hosts behind a registered Internet gateway.

These files also assume that most of your neighbors use domain-based UUCP addressing; that is, instead of naming hosts as host!user they will use host.domain!user. The configuration files can be customized to work around this, but it is more complex.

Our configuration files are processed by m4 to facilitate local customization; the directory cf of the sendmail distribution directory contains the source files along with several subdirectories, as follows:


cf
Both site-dependent and site-independent descriptions of hosts. These can be literal host names (for example, ucbvax.mc) when the hosts are gateways or more general descriptions (such as generic-solaris2.mc as a general description of an SMTP-connected host running Solaris 2.x. Files ending .mc (``Master Configuration'') are the input descriptions; the output is in the corresponding .cf file.

domain
Site-dependent subdomain descriptions. These are tied to the way your organization wants to do addressing. For example, domain/CS.Berkeley.EDU.m4 is our description for hosts in the CS.Berkeley.EDU subdomain. These are referenced using the DOMAIN m4 macro in the .mc file.

feature
Definitions of specific features that some particular host in your site might want. These are referenced using the FEATURE m4 macro. An example feature is use_cw_file (which tells sendmail to read an /etc/sendmail.cw file on startup to find the set of local names).

hack
Local hacks, referenced using the HACK m4 macro. It is recommended that these be avoided.

m4
Site-independent m4(1) include files that have information common to all configuration files. This can be thought of as a #include directory.

mailer
Definitions of mailers, referenced using the MAILER m4 macro. The mailer types that are known in this distribution are ``fax'', ``local'', ``smtp'', ``uucp'', and ``usenet''. For example, to include support for the UUCP-based mailers, use MAILER(uucp).

ostype
Definitions describing various operating system environments (such as the location of support files). These are referenced using the OSTYPE m4 macro.

sh
Shell files used by the m4 build process. You shouldn't have to amend these.

siteconfig
Local UUCP connectivity information. They normally contain lists of site information, for example:
SITE(contessa)
SITE(hoptoad)
SITE(nkainc)
SITE(well)
They are referenced using the SITECONFIG macro:
SITECONFIG(site.config.file, name_of_site, X)
X is the macro/class name to use. It can be ``U'' (indicating locally connected hosts) or one of ``W'', ``X'', or ``Y'' for up to three remote UUCP hubs. This directory has been supplanted by the mailertable feature; any new configurations should use that feature to do UUCP (and other) routing.
If you are in a new domain (for example, a company), you will probably want to create a cf/domain file for your domain. This consists primarily of relay definitions and features you want enabled site-wide: for example, Berkeley's domain definition defines relays for BitNET and UUCP. These are specific to Berkeley, and should be fully-qualified Internet-style domain names. Please check to make certain they are reasonable for your domain.

Subdomains at Berkeley are also represented in the cf/domain directory. For example, the domain CS.Berkeley.EDU is the Computer Science subdomain, EECS.Berkeley.EDU is the Electrical Engineering and Computer Sciences subdomain, and S2K.Berkeley.EDU is the Sequoia 2000 subdomain. You will probably have to add an entry to this directory

You will have to use or create .mc files in the cf/cf subdirectory for your hosts. This is detailed in the cf/README file.


© 2000 The Santa Cruz Operation, Inc. All rights reserved.