readme

早期freebsd实现

		NEW SENDMAIL CONFIGURATION FILES

		Eric Allman <[e-mail]>

		@(#)README	8.28 (Berkeley) 4/14/94


This document describes the sendmail configuration files being used
at Berkeley.  These use features in the new (R8) sendmail, and although
there is an ``OLDSENDMAIL'' mode, they haven't really been tested on
old versions of sendmail and cannot be expected to work well.

These configuration files are probably not as general as previous
versions, and don't handle as many of the weird cases automagically.
I was able to simplify by them for two reasons.  First, the network
has become more consistent -- for example, at this point, everyone
on the internet is supposed to be running a name server, so hacks to
handle NIC-registered hosts can go away.  Second, I assumed that a
subdomain would be running SMTP internally -- UUCP is presumed to be
a long-haul protocol.  I realize that this is not universal, but it
does describe the vast majority of sites with which I am familiar,
including those outside the US.

Of course, the downside of this is that if you do live in a weird
world, things are going to get weirder for you.  I'm sorry about that,
but at the time we at Berkeley had a problem, and it seemed like the
right thing to do.

This package requires a post-V7 version of m4; if you are running the
4.2bsd, SysV.2, or 7th Edition version, I suggest finding a friend with
a newer version.  You can m4-expand on their system, then run locally.
SunOS's /usr/5bin/m4 or BSD-Net/2's m4 both work.  GNU m4 version 1.1
also works.  Unfortunately, I'm told that the M4 on BSDI 1.0 doesn't
work -- you'll have to use a Net/2 or GNU version.

IF YOU DON'T HAVE A BERKELEY MAKE, don't despair!  Just run
"m4 foo.mc > foo.cf" -- that should be all you need.  There is also
a fairly crude (but functional) Makefile.dist that works on the
old version of make.

To get started, you may want to look at tcpproto.mc (for TCP-only
sites), uucpproto.mc (for UUCP-only sites), and clientproto.mc (for
clusters of clients using a single mail host).  Others are versions
that we use at Berkeley, although not all are in current use.  For
example, ucbarpa has gone away, but I've left ucbarpa.mc in because
it demonstrates some interesting techniques.

I'm not pretending that this README describes everything that these
configuration files can do; clever people can probably tweak them
to great effect.  But it should get you started.

*******************************************************************
***  BE SURE YOU CUSTOMIZE THESE FILES!  They have some		***
***  Berkeley-specific assumptions built in, such as the name	***
***  of our UUCP-relay.  You'll want to create your own domain	***
***  description, and use that in place of domain/Berkeley.m4.	***
*******************************************************************


+--------------------------+
| INTRODUCTION AND EXAMPLE |
+--------------------------+

Configuration files are contained in the subdirectory "cf", with a
suffix ".mc".  They must be run through "m4" to produce a ".cf" file.

Let's examine a typical .mc file (cf/cs-exposed.mc):

	divert(-1)
	#
	# Copyright (c) 1983 Eric P. Allman
	# Copyright (c) 1988 The Regents of the University of California.
	# All rights reserved.
	#
	# Redistribution and use in source and binary forms are permitted
	# provided that the above copyright notice and this paragraph are
	# duplicated in all such forms and that any documentation,
	# advertising materials, and other materials related to such
	# distribution and use acknowledge that the software was developed
	# by the University of California, Berkeley.  The name of the
	# University may not be used to endorse or promote products derived
	# from this software without specific prior written permission.
	# THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	# IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	# WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	#

The divert(-1) will delete the crud in the resulting output file.
The copyright notice is what your lawyers require.  Our lawyers require
the one that I've included in my files. A copyleft is a copyright by
another name.

The next line MUST be

	include(`../m4/cf.m4')

This will pull in the M4 macros you will need to make sense of
everything else.  As the saying goes, don't think about it, just
do it.  If you don't do it, don't bother reading the rest of this
file.

	VERSIONID(`<SCCS or RCS version id>')

VERSIONID is a macro that stuffs the version information into the
resulting file.  We use SCCS; you could use RCS, something else, or
omit it completely.  This is not the same as the version id included
in SMTP greeting messages -- this is defined in m4/version.m4.

	DOMAIN(cs.exposed)

This example exposes the host inside of the CS subdomain -- that is,
it doesn't try to hide the name of the workstation to the outside
world.  Changing this to DOMAIN(cs.hidden) would have made outgoing
messages refer to "<username>@CS.Berkeley.EDU" instead of using the
local hostname.  Internally this is effected by using
"MASQUERADE_AS(CS.Berkeley.EDU)".

	MAILER(smtp)

These describe the mailers used at the default CS site site.  The
local mailer is always included automatically.


+--------+
| OSTYPE |
+--------+

Note that cf/cs-exposed.mc omits an OSTYPE macro -- this assumes
default Computer Science Division environment.  There are several
explicit environments available: bsd4.3, bsd4.4, hpux, irix, osf1,
riscos4.5, sunos3.5, sunos4.1, and ultrix4.1.  These change things
like the location of the alias file and queue directory.  Some of
these files are identical to one another.

Operating system definitions are easy to write.  They may define
the following variables (everything defaults, so an ostype file
may be empty).

ALIAS_FILE		[/etc/aliases] The location of the text version
			of the alias file(s).  It can be a comma-separated
			list of names (but be sure you quote values with
			comments in them -- for example, use
				define(`ALIAS_FILE', `a,b')
			to get "a" and "b" both listed as alias files;
			otherwise the define() primitive only sees "a").
HELP_FILE		[/usr/lib/sendmail.hf] The name of the file
			containing information printed in response to
			the SMTP HELP command.
QUEUE_DIR		[/var/spool/mqueue] The directory containing
			queue files.
STATUS_FILE		[/etc/sendmail.st] The file containing status
			information.
LOCAL_MAILER_PATH	[/bin/mail] The program used to deliver local mail.
LOCAL_MAILER_FLAGS	[rmn] The flags used by the local mailer.  The
			flags lsDFM are always included.
LOCAL_MAILER_ARGS	[mail -d $u] The arguments passed to deliver local
			mail.
LOCAL_SHELL_PATH	[/bin/sh] The shell used to deliver piped email.
LOCAL_SHELL_FLAGS	[eu] The flags used by the shell mailer.  The
			flags lsDFM are always included.
LOCAL_SHELL_ARGS	[sh -c $u] The arguments passed to deliver "prog"
			mail.
USENET_MAILER_PATH	[/usr/lib/news/inews] The name of the program
			used to submit news.
USENET_MAILER_FLAGS	[rlsDFMmn] The mailer flags for the usenet mailer.
USENET_MAILER_ARGS	[-m -h -n] The command line arguments for the
			usenet mailer.
USENET_MAILER_MAX	[100000] The maximum size of messages that will
			be accepted by the usenet mailer.
SMTP_MAILER_FLAGS	[undefined] Flags added to SMTP mailer.  Default
			flags are `mDFMUX' (and `a' for esmtp mailer).
SMTP_MAILER_MAX		[undefined] The maximum size of messages that will
			be transported using the smtp or esmtp mailers.
UUCP_MAILER_FLAGS	[undefined] Flags added to UUCP mailer.  Default
			flags are `DFMhuU' (and `m' for suucp mailer, minus
			`U' for uucp-dom mailer).
UUCP_MAILER_ARGS	[uux - -r -z -a$f -gC $h!rmail ($u)] The arguments
			passed to the UUCP mailer.
UUCP_MAX_SIZE		[100000] The maximum size message accepted for
			transmission by the UUCP mailers.
FAX_MAILER_PATH		[/usr/local/lib/fax/mailfax] The program used to
			submit FAX messages.
FAX_MAILER_MAX		[100000] The maximum size message accepted for
			transmission by FAX.

+---------+
| DOMAINS |
+---------+

You will probably want to collect domain-dependent defines into one
file, referenced by the DOMAIN macro.  For example, our Berkeley
domain file includes definitions for several internal distinguished
hosts:

UUCP_RELAY	The host that will forward UUCP-addressed email.
		If not defined, all UUCP sites must be directly
		connected.
BITNET_RELAY	The host that will forward BITNET-addressed email.
		If not defined, the .BITNET pseudo-domain won't work.
LOCAL_RELAY	The site that will handle unqualified names -- that
		is, names with out an @domain extension.  If not set,
		they are assumed to belong on this machine.  This
		allows you to have a central site to store a
		company- or department-wide alias database.  This
		only works at small sites, and there are better
		methods.

Each of these can be either ``mailer:hostname'' (in which case the
mailer is the internal mailer name, such as ``suucp'' and the hostname
is the name of the host as appropriate for that mailer) or just a
``hostname'', in which case a default mailer type (usually ``relay'',
a variant on SMTP) is used.  WARNING: if you have a wildcard MX
record matching your domain, you probably want to define these to
have a trailing dot so that you won't get the mail diverted back
to yourself.

The domain file can also be used to define a domain name, if needed
(using "DD<domain>") and set certain site-wide features.  If all hosts
at your site masquerade behind one email name, you could also use
MASQUERADE_AS here.

You do not have to define a domain -- in particular, if you are a
single machine sitting off somewhere, it is probably more work than
it's worth.  This is just a mechanism for combining "domain dependent
knowledge" into one place.

+---------+
| MAILERS |
+---------+

There are fewer mailers supported in this version than the previous
version, owing mostly to a simpler world.

local		The local and prog mailers.  You will almost always
		need these; the only exception is if you relay ALL
		your mail to another site.  This mailer is included
		automatically.

smtp		The Simple Mail Transport Protocol mailer.  This does
		not hide hosts behind a gateway or another other
		such hack; it assumes a world where everyone is
		running the name server.  This file actually defines
		three mailers: "smtp" for regular (old-style) SMTP to
		other servers, "esmtp" for extended SMTP to other
		servers, and "relay" for transmission to our
		RELAY_HOST or MAILER_HUB.

uucp		The Unix-to-Unix Copy Program mailer.  Actually, this
		defines two mailers, "uucp" and "suucp".  The latter
		is for when you know that the UUCP mailer at the other
		end can handle multiple recipients in one transfer.
		When you invoke this, sendmail looks for all names in
		the $=U class and sends them to the uucp-old mailer; all
		names in the $=Y class are sent to uucp-new; and all
		names in the $=Z class are sent to uucp-uudom.  Note that
		this is a function of what version of rmail runs on
		the receiving end, and hence may be out of your control.
		If smtp is defined, it also defines "uucp-dom" and
		"uucp-uudom" mailers that use domain-style rewriting.
		See the section below describing UUCP mailers in more
		detail.

usenet		Usenet (network news) delivery.  If this is specified,
		an extra rule is added to ruleset 0 that forwards all
		local email for users named ``group.usenet'' to the
		``inews'' program.  Note that this works for all groups,
		and may be considered a security problem.

fax		Facsimile transmission.  This is experimental and based
		on Sam Leffler's FlexFAX software.  For more information,
		see below.

pop		Post Office Protocol.


+----------+
| FEATURES |
+----------+

Special features can be requested using the "FEATURE" macro.  For
example, the .mc line:

	FEATURE(use_cw_file)

tells sendmail that you want to have it read an /etc/sendmail.cw
file to get values for class $=w.  The FEATURE may contain a single
optional parameter -- for example:

	FEATURE(mailertable, dbm /usr/lib/mailertable)

Available features are:

use_cw_file	Read the file /etc/sendmail.cw file to get alternate
		names for this host.  This might be used if you were
		on a host that MXed for a dynamic set of other
		hosts.  If the set is static, just including the line
		"Cw<name1> <name2> ..." is probably superior.
		The actual filename can be overridden by redefining
		confCW_FILE.

redirect	Reject all mail addressed to "address.REDIRECT" with
		a ``551 User not local; please try <address>'' message.
		If this is set, you can alias people who have left
		to their new address with ".REDIRECT" appended.

nouucp		Don't do anything special with UUCP addresses at all.