try to make sure that path-addrs always have <angle brackets>

[unix-history] / usr / src / usr.sbin / sendmail / cf / README

diff --git a/usr/src/usr.sbin/sendmail/cf/README b/usr/src/usr.sbin/sendmail/cf/README
index 910ff29..86fb080 100644 (file)
--- a/usr/src/usr.sbin/sendmail/cf/README
+++ b/usr/src/usr.sbin/sendmail/cf/README
@@ -1,42 +1,63 @@
-@(#)README     2.1 (Berkeley) %G%
+
+
+               NEW SENDMAIL CONFIGURATION FILES
+
+               Eric Allman <eric@CS.Berkeley.EDU>
+
+               @(#)README      8.19 (Berkeley) %G%
+

 
 This document describes the sendmail configuration files being used
 
 This document describes the sendmail configuration files being used

-at Berkeley.  There have been several previous versions.  This file
-is being written on 24 July 1991, and will probably not be generally
-available for several months.
+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.

 
 

-INSTALLING A NEW SITE CONFIGURATION
+These configuration files are probably not as general as previous
+versions, and don't handle as many of the wierd 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.

 
 

-Configuration files are contained in the subdirectory "cf", with a
-suffix ".mc".  They must be run through "m4" to produce a ".cf" file.
+Of course, the downside of this is that if you do live in a wierd
+world, things are going to get wierder 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.

 
 

-Every .mc file SHOULD begin with:
+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.

 
 

-       divert(-1)
-       COPYRIGHT NOTICE
-       divert(0)
+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.

 
 

-If you don't care about copyrights, you can omit this.  If you try
-to patent this, I'll be very, very pissed.  I haven't patented a lot
-of hot ideas so that you can use them; I expect reciprocal courtesy.
-A copyleft is a copyright by another name.
+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.

 
 

-The copyright, if any, MUST be followed by:
+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.

 
 

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

 
 

-At this point, let me make one thing perfectly clear.  I am a rope
-salesman.  I sell you rope.  I haven't produced a new M4 system
-that detects latent bugs, nor have I tried to fix the old one.
-(However, I have decided to rely on a post-V7 version; 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.)
+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):
 
 
 Let's examine a typical .mc file (cf/cs-exposed.mc):
 


@@ -59,69 +80,966 @@ Let's examine a typical .mc file (cf/cs-exposed.mc):
        # WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        #
 
        # WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        #
 

-If you copy this file and modify it, you should maintain this copyright
-notice.  If you actually start from scratch you can delete it -- but be
-honest!
+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')
 
 
        include(`../m4/cf.m4')
 

-You need this line!
+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(@(#)README    2.1 (Berkeley) %G%)
+       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
 
 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.
+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)dnl
+       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
 
 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.  This can also be effected by using:
+local hostname.  Internally this is effected by using
+"MASQUERADE_AS(CS.Berkeley.EDU)".

 
 

-       define(`MASQUERADE_AS', `masquerade.host.name.domain.name')dnl
+       MAILER(smtp)

 
 

-in the ".mc" file.
+These describe the mailers used at the default CS site site.  The
+local mailer is always included automatically.

 
 

-       MAILER(local)dnl
-       MAILER(smtp)dnl

 
 

-These describe the mailers used at the default CS site site.  
++--------+
+| OSTYPE |
++--------+

 
 Note that cf/cs-exposed.mc omits an OSTYPE macro -- this assumes
 default Computer Science Division environment.  There are several
 
 Note that cf/cs-exposed.mc omits an OSTYPE macro -- this assumes
 default Computer Science Division environment.  There are several

-environments available: bsd4.3, bsd4.4, riscos4.5, sunos3.5,
-sunos4.1, and ultrix4.1.  These change things like the location
-of the alias file and queue directory.
+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.

 
 

-MAILERS
+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.
+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 $u] The arguments passed to deliver "prog"
+                       mail.
+USENET_MAILER_PATH     [/usr/lib/news/inews] The name of the program
+                       used to submit news.
+USENET_MAILER_FLAGS    [rlsDFMmn] The mailer flags for the usenet mailer.
+USENET_MAILER_ARGS     [-m -h -n] The command line arguments for the
+                       usenet mailer.
+SMTP_MAILER_FLAGS      [undefined] Flags added to SMTP mailer.  Default
+                       flags are `mDFMUX' (and `a' for esmtp mailer).
+UUCP_MAILER_FLAGS      [undefined] Flags added to UUCP mailer.  Default
+                       flags are `DFMhuU' (and `m' for suucp mailer, minus
+                       `U' for uucp-dom mailer).
+UUCP_MAILER_ARGS       [uux - -r -z -a$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.
+HOSTMAP_SPEC           [dbm -o /etc/hostmap] The value for the builtin
+                       hostmap key definition.  You can redefine this
+                       to change the class, flags, and filename of
+                       the hostmap.  The default flag (-o) makes this
+                       map optional.
+
++---------+
+| 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
 
 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.
+               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
 
 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.
+               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.
 
 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.
+
+nocanonify     Don't pass addresses to $[ ... $] for canonification.
+               This would generally only be used by sites that only
+               act as mail gateways or which have user agents that do
+               full canonification themselves.  You may also want to
+               use "define(`confBIND_OPTS',`-DNSRCH -DEFNAMES')" to
+               turn off the usual resolver options that do a similar
+               thing.
+
+notsticky      By default, email sent to "user@local.host" are marked
+               as "sticky" -- that is, the local addresses aren't
+               matched against UDB and don't go through ruleset 5.
+               This features disables this treatment.  It would
+               normally be used on network gateway machines.
+
+mailertable    Include a "mailer table" which can be used to override
+               routing for particular domains.  The argument of the
+               FEATURE may be the key definition.  If none is specified,
+               the definition used is:
+                       hash -o /etc/mailertable
+               Keys in this database are fully qualified domain names
+               or partial domains preceded by a dot -- for example,
+               "vangogh.CS.Berkeley.EDU" or ".CS.Berkeley.EDU".
+               Values must be of the form:
+                       mailer:domain
+               where "mailer" is the internal mailer name, and "domain"
+               is where to send the message.  These maps are not
+               reflected into the message header.
+
+domaintable    Include a "domain table" which can be used to provide
+               full domains on unqualified (single word) hosts.  The
+               argument of the FEATURE may be the key definition.  If
+               none is specified, the definition used is:
+                       hash -o /etc/domaintable
+               The key in this table is the unqualified host name; the
+               value is the fully qualified domain.  Anything in the
+               domaintable is reflected into headers; that is, this
+               is done in ruleset 3.
+
+bitdomain      Look up bitnet hosts in a table to try to turn them into
+               internet addresses.  The table can be built using the
+               bitdomain program contributed by John Gardiner Myers.
+               The argument of the FEATURE may be the key definition; if
+               none is specified, the definition used is:
+                       hash -o /etc/bitdomain.db
+               Keys are the bitnet hostname; values are the corresponding
+               internet hostname.
+
+uucpdomain     Similar feature for UUCP hosts.  The default map definition
+               is:
+                       hash -o /etc/uudomain.db
+               At the moment there is no automagic tool to build this
+               database.
+
+always_add_domain
+               Include the local host domain even on locally delivered
+               mail.  Normally it is not added unless it is already
+               present.
+
+allmasquerade  If masquerading is enabled (using MASQUERADE_AS), this
+               feature will cause recipient addresses to also masquerade
+               as being from the masquerade host.  Normally they get
+               the local hostname.  Although this may be right for
+               ordinary users, it can break local aliases.  For example,
+               if you send to "localalias", the originating sendmail will
+               find that alias and send to all members, but send the
+               message with "To: localalias@masqueradehost".  Since that
+               alias likely does not exist, replies will fail.  Use this
+               feature ONLY if you can guarantee that the ENTIRE
+               namespace on your masquerade host supersets all the
+               local entries.
+
+nodns          We aren't running DNS at our site (for example,
+               we are UUCP-only connected).  It's hard to consider
+               this a "feature", but hey, it had to go somewhere.
+
+nullclient     This is a special case -- it creates a stripped down
+               configuration file containing nothing but support for
+               forwarding all mail to a central hub via a local
+               SMTP-based network.  The argument is the name of that
+               hub.
+               
+               The only other feature that should be used in conjunction
+               with this one is "nocanonify" (this causes addresses to
+               be sent unqualified via the SMTP connection; normally
+               they are qualifed with the masquerade name, which
+               defaults to the name of the hub machine).  No mailers
+               should be defined.  No aliasing or forwarding is done.
+
+
++-------+
+| HACKS |
++-------+
+
+Some things just can't be called features.  To make this clear,
+they go in the hack subdirectory and are referenced using the HACK
+macro.  These will tend to be site-dependent.  The release
+includes the Berkeley-dependent "cssubdomain" hack (that makes
+sendmail accept local names in either Berkeley.EDU or CS.Berkeley.EDU;
+this is intended as a short-term aid while we move hosts into
+subdomains.
+
+
++--------------------+
+| SITE CONFIGURATION |
++--------------------+
+
+Complex sites will need more local configuration information, such as
+lists of UUCP hosts they speak with directly.  This can get a bit more
+tricky.  For an example of a "complex" site, see cf/ucbvax.mc.
+
+The SITECONFIG macro allows you to indirectly reference site-dependent
+configuration information stored in the siteconfig subdirectory.  For
+example, the line
+
+       SITECONFIG(uucp.ucbvax, ucbvax, U)
+
+reads the file uucp.ucbvax for local connection information.  The
+second parameter is the local name (in this case just "ucbvax" since
+it is locally connected, and hence a UUCP hostname) and the name of
+the class in which to store the host information.  Another SITECONFIG
+line reads
+
+       SITECONFIG(uucp.ucbarpa, ucbarpa.Berkeley.EDU, W)
+
+This says that the file uucp.ucbarpa contains the list of UUCP sites
+connected to ucbarpa.Berkeley.EDU.  The $=W class will be used to
+store this list.  [The machine ucbarpa is gone now, but I've left
+this out-of-date configuration file around to demonstrate how you
+might do this.]
+
+The siteconfig file (e.g., siteconfig/uucp.ucbvax.m4) contains nothing
+more than a sequence of SITE macros describing connectivity.  For
+example:
+
+       SITE(cnmat)
+       SITE(sgi olympus)
+
+The second example demonstrates that you can use two names on the
+same line; these are usually aliases for the same host (or are at
+least in the same company).
+
+
++--------------------+
+| USING UUCP MAILERS |
++--------------------+
+
+It's hard to get UUCP mailers right because of the extremely ad hoc
+nature of UUCP addressing.  These config files are really designed
+for domain-based addressing, even for UUCP sites.
+
+There are four UUCP mailers available.  The choice of which one to
+use is partly a matter of local preferences and what is running at
+the other end of your UUCP connection.  Unlike good protocols that
+define what will go over the wire, UUCP uses the policy that you
+should do what is right for the other end; if they change, you have
+to change.  This makes it hard to do the right thing, and discourages
+people from updating their software.  In general, if you can avoid
+UUCP, please do.
+
+The major choice is whether to go for a domainized scheme or a
+non-domainized scheme.  This depends entirely on what the other
+end will recognize.  If at all possible, you should encourage the
+other end to go to a domain-based system -- non-domainized addresses
+don't work entirely properly.
+
+The four mailers are:
+
+    uucp-old (obsolete name: "uucp")
+       This is the oldest, the worst (but the closest to UUCP) way of
+       sending messages accros UUCP connections.  It does bangify
+       everything and prepends $U (your UUCP name) to the sender's
+       address (which can already be a bang path itself).  It can
+       only send to one address at a time, so it spends a lot of
+       time copying duplicates of messages.  Avoid this if at all
+       possible.
+
+    uucp-new (obsolete name: "suucp")
+       The same as above, except that it assumes that in one rmail
+       command you can specify several recipients.  It still has a
+       lot of other problems.
+
+    uucp-dom
+       This UUCP mailer keeps everything as domain addresses.
+       Basically, it uses the SMTP mailer rewriting rules.
+
+       Unfortunately, a lot of UUCP mailer transport agents require
+       bangified addresses in the envelope, although you can use
+       domain-based addresses in the message header.  (The envelope
+       shows up as the From_ line on UNIX mail.)  So....
+
+    uucp-uudom
+       This is a cross between uucp-new (for the envelope addresses)
+       and uucp-dom (for the header addresses).  It bangifies the
+       envelope sender (From_ line in messages) without adding the
+       local hostname, unless there is no host name on the address
+       at all (e.g., "wolf") or the host component is a UUCP host name
+       instead of a domain name ("somehost!wolf" instead of
+       "some.dom.ain!wolf").
+
+Examples:
+
+We are on host grasp.insa-lyon.fr (UUCP host name "grasp").  The
+following summarizes the sender rewriting for various mailers.
+
+Mailer          sender         rewriting in the envelope
+------         ------          -------------------------
+uucp-{old,new} wolf            grasp!wolf
+uucp-dom       wolf            wolf@grasp.insa-lyon.fr
+uucp-uudom     wolf            grasp.insa-lyon.fr!wolf
+
+uucp-{old,new} wolf@fr.net     grasp!fr.net!wolf
+uucp-dom       wolf@fr.net     wolf@fr.net
+uucp-uudom     wolf@fr.net     fr.net!wolf
+
+uucp-{old,new} somehost!wolf   grasp!somehost!wolf
+uucp-dom       somehost!wolf   somehost!wolf@grasp.insa-lyon.fr
+uucp-uudom     somehost!wolf   grasp.insa-lyon.fr!somehost!wolf
+
+If you are using one of the domainized UUCP mailers, you really want
+to convert all UUCP addresses to domain format -- otherwise, it will
+do it for you (and probably not the way you expected).  For example,
+if you have the address foo!bar!baz (and you are not sending to foo),
+the heuristics will add the @uucp.relay.name or @local.host.name to
+this address.  However, if you map foo to foo.host.name first, it
+will not add the local hostname.  You can do this using the uucpdomain
+feature.
+
+
++-------------------+
+| TWEAKING RULESETS |
++-------------------+
+
+For more complex configurations, you can define special rules.
+The macro LOCAL_RULE_3 introduces rules that are used in canonicalizing
+the names.  Any modifications made here are reflected in the header.
+
+A common use is to convert old UUCP addreses to SMTP addresses using
+the UUCPSMTP macro.  For example:
+
+       LOCAL_RULE_3
+       UUCPSMTP(decvax,        decvax.dec.com)
+       UUCPSMTP(research,      research.att.com)
+
+will cause addresses of the form "decvax!user" and "research!user"
+to be converted to "user@decvax.dec.com" and "user@research.att.com"
+respectively.
+
+This could also be used to look hosts in a database map:
+
+       LOCAL_RULE_3
+       R$* < @ $+ > $*         $: $1 < @ $(hostmap $2 $) > $3
+
+This map would be defined in the LOCAL_CONFIG portion, as shown below.
+
+Similarly, LOCAL_RULE_0 can be used to introduce new parsing rules.
+For example, new rules are needed to parse hostnames that you accept
+via MX records.  For example, you might have:
+
+       LOCAL_RULE_0
+       R$+ < @ cnmat.Berkeley.EDU >    $#uucp $@ cnmat $: $1
+
+You would use this if you had installed an MX record for cnmat.Berkeley.EDU
+pointing at this host; this rule catches the message and forwards it on
+using UUCP.
+
+You can also tweak rulesets 1 and 2 using LOCAL_RULE_1 and LOCAL_RULE_2.
+These rulesets are normally empty.
+
+A similar macro is LOCAL_CONFIG.  This introduces lines added after the
+boilerplate option setting but before rulesets, and can be used to
+declare local database maps or whatever.  For example:
+
+       LOCAL_CONFIG
+       Khostmap hash /etc/hostmap.db
+       Kyplocal nis -m hosts.byname
+
+
++---------------------------+
+| MASQUERADING AND RELAYING |
++---------------------------+

 
 

-HIERARCHY
+You can have your host masquerade as another using
+
+       MASQUERADE_AS(host.domain)
+
+This causes outgoing SMTP mail to be labelled as coming from the
+indicated domain, rather than $j.  One normally masquerades as one
+of your own subdomains (for example, it's unlikely that I would
+choose to masquerade as an MIT site).
+
+The masquerade name is not normally canonified, so it is important
+that it be your One True Name, that is, fully qualified and not a
+CNAME.
+
+there are always users that need to be "exposed" -- that is, their
+internal site name should be displayed instead of the masquerade name.
+Root is an example.  You can add users to this list using
+
+       EXPOSED_USER(usernames)
+
+This adds users to class E; you could also use something like
+
+       FE/etc/sendmail.cE
+
+You can also arrange to relay all unqualified names (that is, names
+without @host) to a relay host.  For example, if you have a central
+email server, you might relay to that host so that users don't have
+to have .forward files or aliases.  You can do this using
+
+       define(`LOCAL_RELAY', mailer:hostname)
+
+The ``mailer:'' can be omitted, in which case the mailer defaults to
+"smtp".  There are some user names that you don't want relayed, perhaps
+because of local aliases.  A common example is root, which may be
+locally aliased.  You can add entries to this list using
+
+       LOCAL_USER(usernames)
+
+This adds users to class L; you could also use something like
+
+       FL/etc/sendmail.cL
+
+If you want all incoming mail sent to a centralized hub, as for a
+shared /var/spool/mail scheme, use
+
+       define(`MAIL_HUB', mailer:hostname)
+
+Again, ``mailer:'' defaults to "smtp".  If you define both LOCAL_RELAY
+and MAIL_HUB, unqualified names and names in class L will be sent to
+the LOCAL_RELAY and other local names will be sent to MAIL_HUB.  For
+example, if are on machine mastodon.CS.Berkeley.EDU, the following
+combinations of settings will have the indicated effects:
+
+email sent to....      eric                      eric@mastodon.CS.Berkeley.EDU
+
+LOCAL_RELAY set to     mail.CS.Berkeley.EDU      (delivered locally)
+mail.CS.Berkeley.EDU
+
+MAIL_HUB set to                mammoth.CS.Berkeley.EDU   mammoth.CS.Berkeley.EDU
+mammoth.CS.Berkeley.EDU
+
+Both LOCAL_RELAY and   mail.CS.Berkeley.EDU      mammoth.CS.Berkeley.EDU
+MAIL_HUB set as above
+
+If you want all outgoing mail to go to a central relay site, define
+SMART_HOST as well.  Briefly:
+
+       LOCAL_RELAY applies to unqualifed names (e.g., "eric").
+       MAIL_HUB applies to names qualified with the name of the
+               local host (e.g., "eric@mastodon.CS.Berkeley.EDU").
+       SMART_HOST applies to names qualified with other hosts.
+
+However, beware that other relays (e.g., UUCP_RELAY, BITNET_RELAY, and
+FAX_RELAY) take precedence over SMART_HOST, so if you really want
+absolutely everything to go to a single central site you will need to
+unset all the other relays -- or better yet, find or build a minimal
+config file that does this.
+
+
++-------------------------------+
+| NON-SMTP BASED CONFIGURATIONS |
++-------------------------------+
+
+These configuration files are designed primarily for use by SMTP-based
+sites.  I don't pretend that they are well tuned for UUCP-only or
+UUCP-primarily nodes (the latter is defined as a small local net
+connected to the rest of the world via UUCP).  However, there is one
+hook to handle some special cases.
+
+You can define a ``smart host'' that understands a richer address syntax
+using:
+
+       define(`SMART_HOST', mailer:hostname)
+
+In this case, the ``mailer:'' defaults to "relay".  Any messages that
+can't be handled using the usual UUCP rules are passed to this host.
+
+If you are on a local SMTP-based net that connects to the outside
+world via UUCP, you can use LOCAL_NET_CONFIG to add appropriate rules.
+For example:
+
+       define(`SMART_HOST', suucp:uunet)
+       LOCAL_NET_CONFIG
+       R$* < @ $* .$m. > $*    $#smtp $@ $2.$m. $: $1 < @ $2.$m. > $3
+
+This will cause all names that end in your domain name ($m) via
+SMTP; anything else will be sent via suucp (smart UUCP) to uunet.
+If you have FEATURE(nocanonify), you may need to omit the dots after
+the $m.  If you are running a local DNS inside your domain which is
+not otherwise connected to the outside world, you probably want to
+use:
+
+       define(`SMART_HOST', smtp:fire.wall.com)
+       LOCAL_NET_CONFIG
+       R$* < @ $* . > $*       $#smtp $@ $2. $: $1 < @ $2. > $3
+
+That is, send directly only to things you found in your DNS lookup;
+anything else goes through SMART_HOST.
+
+If you are not running DNS at all, it is important to use
+FEATURE(nodns) to avoid having sendmail queue everything waiting
+for the name server to come up.
+
+
++-----------+
+| WHO AM I? |
++-----------+
+
+Normally, the $j macro is automatically defined to be your fully
+qualified domain name (FQDN).  Sendmail does this by getting your
+host name using gethostname and then calling gethostbyname on the
+result.  For example, in some environments gethostname returns
+only the root of the host name (such as "foo"); gethostbyname is
+supposed to return the FQDN ("foo.bar.com").  In some (fairly rare)
+cases, gethostbyname may fail to return the FQDN.  In this case
+you MUST define confDOMAIN_NAME to be your fully qualified domain
+name.  This is usually done using:
+
+       Dmbar.com
+       define(`confDOMAIN_NAME', `$w.$m')dnl
+
+
++--------------------+
+| USING MAILERTABLES |
++--------------------+
+
+To use FEATURE(mailertable), you will have to create an external
+database containing the routing information for various domains.
+For example, a mailertable file in text format might be:
+
+       .my.domain              xnet:%1.my.domain
+       uuhost1.my.domain       suucp:uuhost1
+       .bitnet                 smtp:relay.bit.net
+
+This should normally be stored in /etc/mailertable.  The actual
+database version of the mailertable is built using:
+
+       makemap hash /etc/mailertable.db < /etc/mailertable
+
+The semantics are simple.  Any LHS entry that does not begin with
+a dot matches the full host name indicated.  LHS entries beginning
+with a dot match anything ending with that domain name -- that is,
+they can be thought of as having a leading "*" wildcard.  Matching
+is done in order of most-to-least qualified -- for example, even
+though ".my.domain" is listed first in the above example, an entry
+of "uuhost1.my.domain" will match the second entry since it is
+more explicit.
+
+The RHS should always be a "mailer:host" pair.  The mailer is the
+configuration name of a mailer (that is, an `M' line in the
+sendmail.cf file).  The "host" will be the hostname passed to
+that mailer.  In domain-based matches (that is, those with leading
+dots) the "%1" may be used to interpolate the wildcarded part of
+the host name.  For example, the first line above sends everything
+addressed to "anything.my.domain" to that same host name, but using
+the (presumably experimental) xnet mailer.
+
+
++--------------------------------+
+| USING USERDB TO MAP FULL NAMES |
++--------------------------------+
+
+The user database was not originally intended for mapping full names
+to login names (e.g., Eric.Allman => eric), but some people are using
+it that way.  (I would recommend that you set up aliases for this
+purpose instead -- since you can specify multiple alias files, this
+is fairly easy.)  The intent was to locate the default maildrop at
+a site, but allow you to override this by sending to a specific host.
+
+If you decide to set up the user database in this fashion, it is
+imperative that you also specify FEATURE(notsticky) -- otherwise,
+e-mail sent to Full.Name@local.host.name will be rejected.
+
+To build the internal form of the user databae, use:
+
+       makemap btree /usr/data/base.db < /usr/data/base.txt
+
+
++------------------+
+| FlexFAX SOFTWARE |
++------------------+
+
+Sam Leffler's FlexFAX software is still in beta test -- but he expects a
+public version out "later this week" [as of 3/1/93].  The following
+blurb is direct from Sam:
+
+       $Header: /usr/people/sam/fax/RCS/HOWTO,v 1.14 93/05/24 11:42:16 sam Exp $
+
+       How To Obtain This Software (in case all you get is this file)
+       --------------------------------------------------------------
+       The source code is available for public ftp on
+           sgi.com                     sgi/fax/v2.1.src.tar.Z
+               (192.48.153.1)
+
+       You can also obtain inst'able images for Silicon Graphics machines from
+           sgi.com                     sgi/fax/v2.1.inst.tar
+               (192.48.153.1)
+
+       For example,
+           % ftp -n sgi.com
+           ....
+           ftp> user anonymous
+           ... <type in password>
+           ftp> cd sgi/fax
+           ftp> binary
+           ftp> get v2.1.src.tar.Z
+
+       In general, the latest version of the 2.1 release of the software is
+       always available as "v2.1.src.tar.Z" or "v2.1.inst.tar" in the ftp
+       directory.  This file is a link to the appropriate released version (so
+       don't waste your time retrieving the linked file as well!) Any files of
+       the form v2.1.*.patch are shell scripts that can be used to patch older
+       versions of the source code.  For example, the file v2.1.0.patch would
+       contain patches to update v2.1.0.tar.Z.  (Note to beta testers: this is
+       different than the naming conventions used during beta testing.) Patch
+       files only work to go between consecutive versions, so if you are
+       multiple versions behind the latest release, you will need to apply
+       each patch file between your current version and the latest.
+
+
+       Obtaining the Software by Electronic Mail
+       -----------------------------------------
+       Do not send me requests for the software; they will be ignored (without
+       response).  If you cannot use FTP at all, there is a service called
+       "ftpmail" available from gatekeeper.dec.com:  you can send e-mail to
+       this machine and it will use FTP to retrieve files for you and send you
+       the files back again via e-mail.  To find out more about the ftpmail
+       service, send a message to "ftpmail@gatekeeper.dec.com" whose body
+       consists of the single line "help".
+
+
+       Obtaining the Software Within Silicon Graphics
+       ----------------------------------------------
+       Internal to Silicon Graphics there are inst'able images on the host
+       flake.asd in the directory /usr/dist.  Thus you can do something like:
+
+           % inst -f flake.asd.sgi.com:/usr/dist/flexfax
+
+       to install the latest version of the software on your machine.
+
+
+       What to do Once You've Retrieved Stuff
+       --------------------------------------
+       The external distributions come in a compressed or uncompressed tar
+       file.  To extract the source distribution:
+
+           % zcat v2.1.src.tar.Z | tar xf -
+
+       (uncompress and extract individual files in current directory).  To
+       unpack and install the client portion of the inst'able distribution:
+
+           % mkdir dist
+           % cd dist; tar xf ../v2.1.inst.tar; cd ..
+           % inst -f dist/flexfax
+           ...
+           inst> go
+
+       (Note, the dist subdirectory is because some versions of inst fail if
+       the files are in the current directory.) Server binaries are also
+       included in the inst'able images as flexfax.server.*.  They are not
+       installed by default, so to get them also you need to do:
+
+           % inst -f flexfax
+           ...
+           inst> install flexfax.server.*
+           inst> go
+
+       The SGI binaries were built for Version 4.0.5H of the IRIX operating
+       system.  They should work w/o problem on earlier versions of the
+       system, but I have not fully tested this.  Also, note that to install a
+       server on an SGI machine, you need to have installed the Display
+       PostScript execution environment product (dps_eoe).  Otherwise, the fax
+       server will not be able to convert PostScript to facsimile for
+       transmission.
+
+       If you are working from the source distribution, look at the file
+       README in the top of the source tree.  If you are working from the inst
+       images, the subsystem flexfax.man.readme contains the README file and
+       other useful pieces of information--the installed files are placed in
+       the directory /usr/local/doc/flexfax).  Basically you will need to run
+       the faxaddmodem script to setup and configure your fax modem.  Consult
+       the README file and the manual page for faxaddmodem for information.
+
+
+       FlexFAX Mail List
+       -----------------
+       A mailing list for users of this software is located on sgi.com.
+       If you want to join this mailing list or have a list-related request
+       such as getting your name removed from it, send a request to
+
+           majordomo@whizzer.wpd.sgi.com
+
+       For example, to subscribe, send the line "subscribe flexfax" in
+       the body of your message.  The line "help" will return a list of
+       the commands understood by the mailing list management software.
+
+       Submissions (including bug reports) should be directed to:
+
+           flexfax@sgi.com
+
+       When corresponding about this software please always specify what
+       version you have, what system you're running on, and, if the problem is
+       specific to your modem, identify the modem and firmware revision.
+
+
++--------------------------------+
+| TWEAKING CONFIGURATION OPTIONS |
++--------------------------------+
+
+There are a large number of configuration options that don't normally
+need to be changed.  However, if you feel you need to tweak them, you
+can define the following M4 variables.  This list is shown in four
+columns:  the name you define, the default value for that definition,
+the option or macro that is affected (either Ox for an option or Dx
+for a macro), and a brief description.  Greater detail of the semantics
+can be found in the Installation and Operations Guide.
+
+Some options are likely to be deprecated in future versions -- that is,
+the option is only included to provide back-compatibility.  These are
+marked with "*".
+
+Remember that these options are M4 variables, and hence may need to
+be quoted.  In particular, arguments with commas will usually have to
+be ``double quoted, like this phrase'' to avoid having the comma
+confuse things.  This is common for alias file definitions and for
+the read timeout.
+
+M4 Variable Name       Default         Mac/Opt Description
+================       =======         ======= ===========
+confMAILER_NAME                MAILER-DAEMON   Dn      The sender name used for
+                                               internally generated
+                                               outgoing messages.
+confFROM_LINE          From $g  $d     Dl      The From_ line used when
+                                               sending to files or programs.
+confFROM_HEADER                $?x$x <$g>$|$g$.        The format of an internally
+                                       Dq      generated From: address.
+confOPERATORS          .:%@!^/[]       Do      Address operator characters.
+confSMTP_LOGIN_MSG     $j Sendmail $v/$Z ready at $b
+                                       De      The initial (spontaneous)
+                                               SMTP greeting message.
+confSEVEN_BIT_INPUT    False           O7      Force input to seven bits?
+confALIAS_WAIT         10              Oa      Wait (in minutes) for alias
+                                               file rebuild.
+confMIN_FREE_BLOCKS    4               Ob      Minimum number of free blocks
+                                               on queue filesystem to accept
+                                               SMTP mail.
+confBLANK_SUB          .               OB      Blank (space) substitution
+                                               character.
+confCON_EXPENSIVE      False           Oc      Connect immediately to
+                                               mailers marked expensive?
+confCHECKPOINT_INTERVAL        10              OC      Checkpoint queue files
+                                               every N recipients.
+confDELIVERY_MODE      background      Od      Default delivery mode.
+confAUTO_REBUILD       False           OD      Automatically rebuild
+                                               alias file if needed.
+confERROR_MODE         (undefined)     Oe      Error message mode.
+confERROR_MESSAGE      (undefined)     OE      Error message header/file.
+confSAVE_FROM_LINES    False           Of      Save extra leading
+                                               From_ lines.
+confTEMP_FILE_MODE     0600            OF      Temporary file mode.
+confDEF_GROUP_ID       1               Og      Default group id.
+confMATCH_GECOS                False           OG      Match GECOS field.
+confMAX_HOP            17              Oh      Maximum hop count.
+confIGNORE_DOTS                False           Oi *    Ignore dot as terminator
+                                               for incoming messages?
+confBIND_OPTS          (empty)         OI      Default options for BIND.
+confMIME_FORMAT_ERRORS True            Oj *    Send error messages as MIME-
+                                               encapsulated messages per
+                                               RFC 1344.
+confFORWARD_PATH       (undefined)     OJ      The colon-separated list of
+                                               places to search for .forward
+                                               files.
+confMCI_CACHE_SIZE     2               Ok      Size of open connection cache.
+confMCI_CACHE_TIMEOUT  5m              OK      Open connection cache timeout.
+confUSE_ERRORS_TO      False           Ol *    Use the Errors-To: header to
+                                               deliver error messages.  This
+                                               should not be necessary because
+                                               of general acceptance of the
+                                               envelope/header distinction.
+confLOG_LEVEL          9               OL      Log level.
+confME_TOO             False           Om      Include sender in group
+                                               expansions.
+confCHECK_ALIASES      True            On      Check RHS of aliases when
+                                               running newaliases.
+confOLD_STYLE_HEADERS  True            Oo *    Assume that headers without
+                                               special chars are old style.
+confDAEMON_OPTIONS     (undefined)     OO      SMTP daemon options.
+confPRIVACY_FLAGS      authwarnings    Op      Privacy flags.
+confCOPY_ERRORS_TO     (undefined)     OP      Address for additional copies
+                                               of all error messages.
+confQUEUE_FACTOR       (undefined)     Oq      Slope of queue-only function
+confREAD_TIMEOUT       (undefined)     Or      SMTP read timeouts.
+confSAFE_QUEUE         True            Os *    Commit all messages to disk
+                                               before forking.
+confMESSAGE_TIMEOUT    5d/4h           OT      Timeout for messages before
+                                               sending error/warning message.
+confTIME_ZONE          USE_SYSTEM      Ot      Time zone info -- can be
+                                               USE_SYSTEM to use the system's
+                                               idea, USE_TZ to use the user's
+                                               TZ envariable, or something
+                                               else to force that value.
+confDEF_USER_ID                1               Ou      Default user id.
+confUSERDB_SPEC                (undefined)     OU      User database specification.
+confFALLBACK_MX                (undefined)     OV      Fallback MX host.
+confTRY_NULL_MX_LIST   False           Ow      If we are the best MX for a
+                                               host and haven't made other
+                                               arrangements, try connecting
+                                               to the host directly; normally
+                                               this would be a config error.
+confQUEUE_LA           8               Ox      Load average at which queue-only
+                                               function kicks in.
+confREFUSE_LA          12              OX      Load average at which incoming
+                                               SMTP connections are refused.
+confWORK_RECIPIENT_FACTOR
+                       (undefined)     Oy      Cost of each recipient.
+confSEPARATE_PROC      False           OY      Run all deliveries in a
+                                               separate process.
+confWORK_CLASS_FACTOR  (undefined)     Oz      Priority multiplier for class.
+confWORK_TIME_FACTOR   (undefined)     OZ      Cost of each delivery attempt.
+confCW_FILE            /etc/sendmail.cw        Name of file used to get the
+                                       Fw      local additions to the $=w
+                                               class.
+confSMTP_MAILER                smtp            -       The mailer name used when
+                                               SMTP connectivity is required.
+                                               Either "smtp" or "esmtp".
+confLOCAL_MAILER       local           -       The mailer name used when
+                                               local connectivity is required.
+                                               Almost always "local".
+confRELAY_MAILER       relay           -       The default mailer name used
+                                               for relaying any mail (e.g.,
+                                               to a BITNET_RELAY, a
+                                               SMART_HOST, or whatever).
+                                               This can reasonably be "suucp"
+                                               if you are on a UUCP-connected
+                                               site.
+confDOMAIN_NAME                (undefined)     Dj      If defined, sets $j.
+
+
++-----------+
+| HIERARCHY |
++-----------+

 
 Within this directory are several subdirectories, to wit:
 
 m4             General support routines.  These are typically
                very important and should not be changed without
 
 Within this directory are several subdirectories, to wit:
 
 m4             General support routines.  These are typically
                very important and should not be changed without

-               contacting your lawyer.
+               very careful consideration.

 
 cf             The configuration files themselves.  They have
                ".mc" suffixes, and must be run through m4 to
 
 cf             The configuration files themselves.  They have
                ".mc" suffixes, and must be run through m4 to


@@ -158,8 +1076,13 @@ hack              Local hacks.  These can be referenced using the HACK
                interest outside the .Berkeley.EDU domain, but who knows?
                We've all got our own peccadilloes.
 
                interest outside the .Berkeley.EDU domain, but who knows?
                We've all got our own peccadilloes.
 

+siteconfig     Site configuration -- e.g., tables of locally connected
+               UUCP sites.
+

 
 

-ADMINISTRATIVE DETAILS
++------------------------+
+| ADMINISTRATIVE DETAILS |
++------------------------+

 
 The following sections detail usage of certain internal parts of the
 sendmail.cf file.  Read them carefully if you are trying to modify
 
 The following sections detail usage of certain internal parts of the
 sendmail.cf file.  Read them carefully if you are trying to modify


@@ -173,30 +1096,40 @@ RULESETS (* means built in to sendmail)
    2 * Recipient rewriting
    3 * Canonicalization
    4 * Post cleanup
    2 * Recipient rewriting
    3 * Canonicalization
    4 * Post cleanup

-   5   Back compatibility for UUCP
-   6   Bottom half of Ruleset 3
-   7   --unused--
-   8   "host dependent cleanup" -- unused?
-   9   change rightmost % to @ -- needed?
+   5 * Local address rewrite (after aliasing)
+  1x   mailer rules (sender qualification)
+  2x   mailer rules (recipient qualification)
+  3x   mailer rules (sender header qualification)
+  4x   mailer rules (recipient header qualification)
+  5x   mailer subroutines (general)
+  6x   mailer subroutines (general)
+  7x   mailer subroutines (general)
+  8x   reserved
+  90   Mailertable host stripping
+  96   Bottom half of Ruleset 3 (ruleset 6 in old sendmail)
+  97   Hook for recursive ruleset 0 call (ruleset 7 in old sendmail)
+  98   Local part of ruleset 0 (ruleset 8 in old sendmail)

 
 
 MAILERS
 
    0   local, prog     local and program mailers
 
 
 MAILERS
 
    0   local, prog     local and program mailers

-   1   smtp            SMTP channel
-   2   uucp
+   1   [e]smtp, relay  SMTP channel
+   2   uucp-*          UNIX-to-UNIX Copy Program
+   3   netnews         Network News delivery
+   4   fax             Sam Leffler's FlexFAX software

 
 
 MACROS
 
    A
    B   Bitnet Relay
 
 
 MACROS
 
    A
    B   Bitnet Relay

-   C   CSNET Relay
-   D
+   C
+   D   The local domain -- usually not needed

    E
    E

-   F
+   F   FAX Relay

    G
    G

-   H
+   H   mail Hub (for mail clusters)

    I
    J
    K
    I
    J
    K


@@ -207,13 +1140,13 @@ MACROS
    P
    Q
    R   Relay (for unqualified names)
    P
    Q
    R   Relay (for unqualified names)

-   S
+   S   Smart Host

    T
    T

-   U   UUCP Relay (all hosts)
+   U   my UUCP name (if I have a UUCP connection)

    V   UUCP Relay (class V hosts)
    W   UUCP Relay (class W hosts)
    X   UUCP Relay (class X hosts)
    V   UUCP Relay (class V hosts)
    W   UUCP Relay (class W hosts)
    X   UUCP Relay (class X hosts)

-   Y   UUCP Relay (class Y hosts)
+   Y   UUCP Relay (all other hosts)

    Z   Version number
 
 
    Z   Version number
 
 


@@ -223,8 +1156,8 @@ CLASSES
    B
    C
    D
    B
    C
    D

-   E
-   F
+   E   addresses that should not seem to come from $M
+   F   hosts we forward for

    G
    H
    I
    G
    H
    I


@@ -234,27 +1167,28 @@ CLASSES
    M
    N
    O   operators that indicate network operations (cannot be in local names)
    M
    N
    O   operators that indicate network operations (cannot be in local names)

-   P
+   P   top level pseudo-domains: BITNET, FAX, UUCP, etc.

    Q
    R
    S
    T
    U   locally connected UUCP hosts
    Q
    R
    S
    T
    U   locally connected UUCP hosts

-   V   UUCP hosts connected to host $V
-   W   UUCP hosts connected to host $X
-   X   UUCP hosts connected to host $Y
-   Y   UUCP hosts connected to host $Z
-   Z
+   V   UUCP hosts connected to relay $V
+   W   UUCP hosts connected to relay $W
+   X   UUCP hosts connected to relay $X
+   Y   locally connected smart UUCP hosts
+   Z   locally connected domain-ized UUCP hosts
+   .   the class containing only a dot

 
 
 M4 DIVERSIONS
 
 
 
 M4 DIVERSIONS
 

-   1   Versions
-   2   Local Ruleset 0 additions
-   3   Local Ruleset 3 additions
-   4
-   5
-   6
+   1   Local host detection and resolution
+   2   Local Ruleset 3 additions
+   3   Local Ruleset 0 additions
+   4   UUCP Ruleset 0 additions
+   5   locally interpreted names (overrides $R)
+   6   local configuration (at top of file)

    7   mailer definitions
    7   mailer definitions

-   8
-   9
+   8   special local name recognition (late in ruleset 3)
+   9   special local rulesets (1 and 2)