hosts file can be space separated instead of tab separated

[unix-history] / usr / src / usr.sbin / sendmail / RELEASE_NOTES

			SENDMAIL RELEASE NOTES
	     @(#)RELEASE_NOTES	8.7.Beta (Berkeley) %G%

This listing shows the version of the sendmail binary, the version
of the sendmail configuration files, the date of release, and a
summary of the changes in that release.

8.7/8.7		95/xx/xx	CURRENTLY IN BETA PRERELEASE!!!
	Fix a problem that could cause sendmail to run out of file
		descriptors due to a trashed data structure after a
		vfork.  Fix from Brian Coan of the Institute for
		Global Communications.
	Change the VRFY response if you have disabled VRFY -- some
		people seemed to think that it was too rude.
	Avoid reference to uninitialized file descriptor if HASFLOCK
		was not defined.  This was used "safely" in the sense
		that it only did a stat, but it would have set the
		map modification time improperly.  Problem pointed out
		by Roy Mongiovi of Georgia Tech.
	Clean up the Subject: line on warning messages and return
		receipts so that they don't say "Returned mail:"; this
		can be confusing.
	Move ruleset entry/exit debugging from 21.2 to 21.1 -- this is
		useful enough to make it worthwhile printing on "-d".
	Avoid logging alias statistics every time you read the alias
		file on systems with no database method compiled in.
	If you have a name with a trailing dot, and you try looking it
		up using gethostbyname without the dot (for /etc/hosts
		compatibility), be sure to turn off RES_DEFNAMES and
		RES_DNSRCH to avoid finding the wrong name accidently.
		Problem noted by Charles Amos of the University of
		Maryland.
	Don't do timeouts in collect if you are not running SMTP.
		There is nothing that says you can't have a long
		running program piped into sendmail (possibly via
		/bin/mail, which just execs sendmail).  Problem reported
		by Don "Truck" Lewis of Silicon Systems.
	Try gethostbyname() even if the DNS lookup fails iff option I
		is not set.  This allows you to have hosts listed in
		NIS or /etc/hosts that are not known to DNS.  It's normally
		a bad idea, but can be useful on firewall machines.  This
		should really be broken out on a separate flag, I suppose.
	Avoid compile warnings against BIND 4.9.3, which uses function
		prototypes.  From Don Lewis of Silicon Systems.
	Avoid possible incorrect diagnosis of DNS-related errors caused
		by things like attempts to resolve uucp names using
		$[ ... $] -- the fix is to clear h_errno at appropriate
		times.  From Kyle Jones of UUNET.
	SECURITY: avoid denial-of-service attacks possible by destroying
		the alias database file by setting resource limits low.
		This involves adding two new compile-time options:
		HASSETRLIMIT (indicating that setrlimit(2) support is
		available) and HASULIMIT (indicating that ulimit(2) support
		is available -- the Release 3 form is used).  The former
		is assumed on BSD-based systems, the latter on System
		V-based systems.  Attack noted by Phil Brandenberger of
		Swarthmore University.
	New syntaxes in test (-bt) mode:
		``.Dmvalue'' will define macro "m" to "value".
		``.Ccvalue'' will add "value" to class "c".
		``.Sruleset'' will dump the contents of the indicated
			ruleset.
		``-ddebug-spec'' is equivalent to the command-line
			-d debug flag.
		``$m'' will print the value of macro "m".
		``/mx host'' returns the MX records for ``host''.
		``/try address'' will parse address, returning the value of
			crackaddr (essentially, the comment information)
			and the parsed address (the same as -bv).
	Somewhat better handling of UNIX-domain socket addresses -- it
		should show the pathname rather than hex bytes.
	Restore ``-ba'' mode -- this reads a file from stdin and parses
		the header for envelope sender information and uses
		CR-LF as message terminators.  It was thought to be
		obsolete (used only for Arpanet NCP protocols), but it
		turns out that the UK ``Grey Book'' protocols require
		that functionality.
	Fix a fix in previous release -- if gethostname and gethostbyname
		return a name without dots, and if a DNS lookup of that
		name fails, wait one minute and try again even if DNS
		not specified in the config file -- the problem is that
		this code is executed before the config file is read.
		This can result in an extra 60 second delay on startup
		if (1) you have DNS compiled in, (2) you are not running
		DNS, (3) your system hostname (as returned by hostname(1))
		has no dot, AND (4) the canonical name listed in /etc/hosts
		or your NIS map has no dot.
	Check for proper domain name on HELO and EHLO commands per
		RFC 1123 section 5.2.5.  Problem noted by Thomas Dwyer III
		of Michigan Technological University.
	Relax chownsafe rules slightly -- old version said that if you
		can't tell if _POSIX_CHOWN_RESTRICTED is set (that is,
		if fpathconf returned EINVAL or ENOSYS), assume that
		chown is not safe.  The new version falls back to whether
		you are on a BSD system or not.  This is important for
		SunOS, which apparently always returns one of those
		error codes.  This impacts whether you can mail to files
		or not.
	Syntax errors such as unbalanced parentheses in the configuration
		file could be omitted if you had "Oem" prior to the
		syntax error in the config file.  Change to always print
		the error message.  It was especially wierd because it
		would cause a "warning" message to be sent to the Postmaster
		for every message sent (but with no transcript).  Problem
		noted by Gregory Paris of Motorola.
	Rewrite collect and putbody to handle full 8-bit data, including
		zero bytes.  These changes are internally extensive, but
		should have minimal impact on external function.
	Allow full words for option names -- if the option letter is
		(apparently) a space, then take the word following -- e.g.,
			O MatchGECOS=TRUE
		The full list of old and new names is as follows:
			7	SevenBitInput
			8	EightBitMode
			A	AliasFile
			a	AliasWait
			B	BlankSub
			b	MinFreeBlocks/MaxMessageSize
			C	CheckpointInterval
			c	HoldExpensive
			D	AutoRebuildAliases
			d	DeliveryMode
			E	ErrorHeader
			e	ErrorMode
			f	SaveFromLine
			F	TempFileMode
			G	MatchGECOS
			H	HelpFile
			h	MaxHopCount
			i	IgnoreDots
			I	ResolverOptions
			J	ForwardPath
			j	SendMimeErrors
			k	ConnectionCacheSize
			K	ConnectionCacheTimeout
			L	LogLevel
			l	UseErrorsTo
			m	MeToo
			n	CheckAliases
			O	DaemonPortOptions
			o	OldStyleHeaders
			P	PostmasterCopy
			p	PrivacyOptions
			Q	QueueDirectory
			q	QueueFactor
			R	DontPruneRoutes
			r, T	Timeout
			S	StatusFile
			s	SuperSafe
			t	TimeZoneSpec
			u	DefaultUser
			U	UserDatabaseSpec
			V	FallbackMXhost
			v	Verbose
			w	TryNullMXList
			x	QueueLA
			X	RefuseLA
			Y	ForkEachJob
			y	RecipientFactor
			z	ClassFactor
			Z	RetryFactor
		To avoid possible problems with an older sendmail,
		configuration level 6 is accepted by this version of
		sendmail; any config file using the new names should
		specify "V6" in the configuration.
	Change address parsing to properly note that a phrase before a
		colon and a trailing semicolon are essentially the same
		as text outside of angle brackets (i.e., sendmail should
		treat them as comments).  This is to handle the
		``group name: addr1, addr2, ..., addrN;'' syntax (it will
		assume that ``group name:'' is a comment on the first
		address and the ``;'' is a comment on the last address).
		This requires config file support to get right.  It does
		understand that :: is NOT this syntax, and can be turned
		off completely by setting the ColonOkInAddresses option.
	Level 6 config files added with new mailer flags:
		    A	Addresses are aliasable.
		    i	Do udb rewriting on envelope as well as header
			sender lines.  Applies to the from address mailer
			flags rather than the recipient mailer flags.
		    j	Do udb rewriting on header recipient addresses.
			Applies to the sender mailer flags rather than the
			recipient mailer flags.
		    k	Disable check for loops when doing HELO command.
		    o	Always run as the mail recipient, even on local
			delivery.
		    w	Check for an /etc/passwd entry for this user.
		    5	Pass addresses through ruleset 5.
		    :	Check for :include: on this address.
		    |	Check for |program on this address.
		    /	Check for /file on this address.
		    @	Look up sender header addresses in the user
			database.  Applies to the mailer flags for the
			mailer corresponding to the envelope sender
			address, rather than to recipient mailer flags.
		Pre-level 6 configuration files set A, w, 5, :, |, /, and @
		on the "local" mailer, the o flag on the "prog" and "*file*"
		mailers, and the ColonOkInAddresses option.
	Eight-to-seven bit MIME conversions.  This borrows ideas from
		John Beck of Hewlett-Packard, who generously contributed
		their implementation to me, which I then didn't use (see
		mime.c for an explanation of why).  This adds the
		EightBitMode option (a.k.a. `8') and an F=8 mailer flag
		to control handling of 8-bit data.  These have to cope with
		two types of 8-bit data: unlabelled 8-bit data (that is,
		8-bit data that is entered without declaring it as 8-bit
		MIME -- technically this is illegal according to the
		specs) and labelled 8-bit data (that is, it was declared
		as 8BITMIME in the ESMTP session or by using the
		-B8BITMIME command line flag).  If the F=8 mailer flag is
		set then 8-bit data is sent to non-8BITMIME machines
		instead of converting to 7 bit (essentially using
		just-send-8 semantics).  The values for EightBitMode are:
		    m	convert unlabelled 8-bit input to 8BITMIME, and do
			any necessary conversion of 8BITMIME to 7BIT
			(essentially, the full MIME option).
		    p	pass unlabelled 8-bit input, but convert labelled
			8BITMIME input to 7BIT as required (default).
		    s	strict adherence: reject unlabelled 8-bit input,
			convert 8BITMIME to 7BIT as required.  The F=8
			flag is ignored.
		Unlabelled 8-bit data is rejected in mode `s' regardless of
			the setting of F=8.
	Add new internal class 'n', which is the set of MIME Content-Types
		which can not be 8 to 7 bit encoded because of other
		considerations.  Types "multipart/*" and "message/*" are
		never directly encoded (although their components can be).
	Add new internal class 'e'.  This is the set of MIME
		Content-Transfer-Encodings that can be converted to
		a seven bit format (Quoted-Printable or Base64).  It is
		preinitialized to contain "7bit", "8bit", and "binary".
	Add C=charset mailer parameter and the the DefaultCharSet option (no
		short name) to set the default character set to use in the
		Content-Type: header when doing encoding of an 8-bit message
		which isn't marked as MIME into MIME format.  If the C=
		parameter is set on the Envelope From address, use that as
		the default encoding; else use the DefaultCharSet option.
		If neither is set, it defaults to "unknown-8bit" as
		suggested by RFC 1428 section 3.
	Allow ``U=user:group'' field in mailer definition to set a default
		user and group that a mailer will be executed as.  This
		overrides the 'u' and 'g' options, and if the `F=S' flag is
		also set, it is the uid/gid that will always be used (that
		is, the controlling address is ignored).  The values may be
		numeric or symbolic; if only a symbolic user is given (no
		group) that user's default group in the passwd file is used
		as the group.  Based on code donated by Chip Rosenthal of
		Unicom.
	Allow `u' option to also accept user:group as a value, in the same
		fashion as the U= mailer option.
	Add the symbolic time zone name in the Arpanet format dates (as
		a comment).  This adds a new compile-time configuration
		flag: TZ_TYPE can be set to TZ_TM_NAME (use the value
		of (struct tm *)->tm_name), TZ_TM_ZONE (use the value
		of (struct tm *)->tm_zone), TZ_TZNAME (use extern char
		*tzname[(struct tm *)->tm_isdst]), TZ_TIMEZONE (use
		timezone()), or TZ_NONE (don't include the comment).  Code
		from Chip Rosenthal.
	The "Timeout" option (formerly "r") is extended to allow suboptions.
		For example,
		    O Timeout.helo = 2m
		There are also two new suboptions "queuereturn" and
		"queuewarn"; these subsume the old T option.  Thus, to
		set them both the preferred new syntax is
		    O Timeout.queuereturn = 5d
		    O Timeout.queuewarn = 4h
	Sort queue by host name instead of by message priority if the
		QueueSortOrder option (no short name) is set is set to
		``host''.  This makes better use of the connection cache,
		but may delay more ``interactive'' messages behind large
		backlogs under some circumstances.  This is probably a
		good option if you have high speed links or don't do lots
		of ``batch'' messages, but less good if you are using
		something like PPP on a 14.4 modem.  Based on code
		contributed by Roy Mongiovi of Georgia Tech (my main
		contribution was to make it configurable).
	Save i-number of df file in qf file to simplify rebuilding of queue
		after disasterous disk crash.  Suggested by Kyle Jones of
		UUNET; closely based on code from KJS DECWRL code written
		by Paul Vixie.  NOTA BENE: The qf files produced by 8.7
		are NOT back compatible with 8.6 -- that is, you can convert
		from 8.6 to 8.7, but not the other direction.
	Add ``F=d'' mailer flag to disable all use of angle brackets in
		route-addrs in envelopes; this is because in some cases
		they can be sent to the shell, which interprets them as
		I/O redirection.
	Don't include error file (option E) with return-receipts; this
		can be confusing.
	Don't send "Warning: cannot send" messages to owner-* or
		*-request addresses.  Suggested by Christophe Wolfhugel
		of the Institut Pasteur, Paris.
	Allow -O command line flag to set long form options.
	Add "MinQueueAge" option to set the minimum time between attempts
		to run the queue.  For example, if the queue interval
		(-q value) is five minutes, but the minimum queue age
		is fifteen minutes, jobs won't be tried more often than
		once every fifteen minutes.  This can be used to give
		you more responsiveness if your delivery mode is set to
		queue-only.
	Allow "fileopen" timeout (default: 60 seconds) for opening
		:include: and .forward files.
	Add "-k", "-v", and "-z" flags to map definitions; these set the
		key field name, the value field name, and the field
		delimiter.  The field delimiter can be a single character
		or the sequence "\t" or "\n" for tab or newline.
		These are for use by NIS+ and similar access methods.
	Add "nisplus" map class.  Takes -k and -v flags to choose the
		key and value field names respectively.  Code donated by
		Sun Microsystems.
	Add "hesiod" map class.  The "file name" is used as the
		"HesiodNameType" parameter to hes_resolve(3).  Returns the
		first value found for the match.  Code donated by Scott
		Hutton of Indiana University.
	Add "netinfo" (NeXT NetInfo) map class.  Maps can have a -k flag to
		specify the name of the property that is searched as the
		key and a -v flag to specify the name of the property that
		is returned as the value (defaults to "members").  The
		default map is "/aliases".
	Add "text" map class.  This does slow, linear searches through
		text files.  The -z flag specifies a column delimiter
		(defaults to any sequence of white space), the -k flag
		sets the key column number, and the -v flag sets the
		value column number.  Lines beginning with `#' are treated
		as comments.
	Add "program" map class to execute arbitrary programs.  The search
		key is presented as the last argument; the output is one
		line read from the programs standard output.  Exit statuses
		are from sysexits.h.
	Add "sequence" map class -- searches maps in sequence until it
		finds a match.  For example, the declarations:
		    Kmap1 ...
		    Kmap2 ...
		    Kmapseq sequence map1 map2
		defines a map "mapseq" that first searches map1; if the
		value is found it is returned immediately, otherwise
		map2 is searched and the value returned.
	Add "switch" map class.  This is much like "sequence" except that
		the ordering is fetched from an external file, usually
		the system service switch.  The parameter is the name of
		the service to switch on, and the maps that it will use
		are this name followed by ".service_type".  For example,
		if the declaration of the map is
		    Ksample switch hosts
		and the system service switch specifies that hosts are
		looked up using dns and nis in that order, then this is
		equivalent to
		    Ksample sequence hosts.dns hosts.nis
		The subordinate maps must already be defined.
	Add "user" map class -- looks up users using getpwnam.  Takes a
		"-v field" flag on the definition that tells what passwd
		entry to return -- legal values are name, passwd, uid, gid,
		gecos, dir, and shell.  Generally expected to be used with
		the -m (matchonly) flag.
	Add "bestmx" map class -- returns the best MX value for the host
		listed as the value.  If there are several "best" MX records
		for this host, one will be chosen at random.
	Add "userdb" map class -- looks up entries in the user database.
		The "file name" is actually the tag that will be used,
		typically "mailname".  If there are multiple entries
		matching the name, the one chosen is undefined.
	Add multiple queue timeouts (both return and warning).  These are
		set by the Precedence: or Priority: header fields to one of
		three values.  If a Priority: is set and has value "normal",
		"urgent", or "non-urgent" the corresponding timeouts are 
		used.  If no priority is set, the Precedence: is consulted;
		if negative, non-urgent timeouts are used; if greater than
		zero, urgent timeouts are used.  Otherwise, normal timeouts
		are used.  The timeouts are set by setting the six timeouts
		queue{warn,return}.{urgent,normal,non-urgent}.
	Fix problem when a mail address is resolved to a $#error mailer
		with a temporary failure indication; it works in SMTP,
		but when delivering locally the mail is silently discarded.
		This patch, from Kyle Jones of UUNET, bounces it instead
		of queueing it (queueing is very hard).
	When using /etc/hosts or NIS-style lookups, don't assume that
		the first name in the list is the best one -- instead,
		search for the first one with a dot.  For example, if
		an /etc/hosts entry reads
		    128.32.149.68	mammoth mammoth.CS.Berkeley.EDU
		this change will use the second name as the canonical
		machine name instead of the initial, unqualified name.
		This heuristic is only used for finding your own name on
		startup, when the system may not be fully configured yet.
	Change dequote map to replace spaces in quoted text with a value
		indicated by the -s flag on the dequote map definition.
		For example, ``Mdequote dequote -s_'' will change
		"Foo Bar" into an unquoted Foo_Bar instead of leaving it
		quoted (because of the space character).  Suggested by Dan
		Oscarsson for use in X.400 addresses.
	Implement long macro names as ${name}; long class names can
		be similarly referenced as $={name} and $~{name}.
		Definitions are (e.g.) ``D{name}value''.  Names that have
		a leading lower case letter or punctuation characters are
		reserved for internal use by sendmail; i.e., config files
		should use names that begin with a capital letter.  Based
		on code contributed by Dan Oscarsson.
	Fix core dump if getgrgid returns a null group list (as opposed
		to an empty group list, that is, a pointer to a list
		with no members).  Fix from Andrew Chang of Sun Microsystems.
	Fix possible core dump if malloc fails -- if the malloc in xalloc
		failed, it called syserr which called newstr which called
		xalloc....  The newstr is now avoided for "panic" messages.
		Reported by Stuart Kemp of James Cook University.
	Improve connection cache timeouts; previously, they were not even
		checked if you were delivering to anything other than an
		IPC-connected host, so a series of (say) local mail
		deliveries could cause cached connections to be open
		much longer than the specified timeout.
	If an incoming message exceeds the maximum message size, stop
		writing the incoming bytes to the queue data file, since
		this can fill your mqueue partition -- this is a possible
		denial-of-service attack.
	Don't reject all numeric local user names unless HESIOD is
		defined.  It turns out that Posix allows all-numeric
		user names.  Fix from Tony Sanders of BSDI.
	Add service switch support.  If the local OS has a service
		switch (e.g., /etc/nsswitch.conf on Solaris) that will
		be used; otherwise, it falls back to using a local
		mechanism based on the ServiceSwitchFile option
		(default: /etc/service.switch).  For example, if the
		service switch lists "files" and "nis" for the aliases
		service, that will be the default lookup order.  Note
		that you can still stack aliases files however, although
		you have to list them explicitly as "implicit:filename".
	Option I (NameServerOptions) no longer sets the "UseNameServer"
		variable which tells whether or not DNS should be considered
		canonical.  This is now determined based on whether or not
		"dns" is in the service list for "hosts".
	Add preliminary support for the ESMTP "DSN" extension (Delivery
		Status Notifications).  This is not yet a standard
		and the implementation is for experimentation only.
		For this reason it only announces itself as "X-DSN-0"
		instead of "DSN".  DSN notifications override
		Return-Receipt-To:.
	Add T=mtstype keyletter to mailer definitions to define the value
		for the Final-MTS-Type: and Remote-MTS-Type: fields in the
		DSN-standard return message.
	Extend heuristic to force running in ESMTP mode to look for the
		six-character string "ESMTP " anywhere in the 220 greeting
		message (not just the second line).  This is to provide
		better compatibility with other ESMTP servers.
	Print sequence number of job when running the queue so you can
		easily see how much progress you have made.  Suggested
		by Peter Wemm of DIALix.
	Map newlines to spaces in logged message-ids; some versions of
		syslog truncate the rest of the line after newlines.
		Suggested by Fletcher Mattox of U. Texas.
	Move up forking for job runs so that if a message is split into
		multiple envelopes you don't get "fork storms" -- this
		also improves the connection cache utilization.
	Accept "<<>>", "<<<>>>", and so forth as equivalent to "<>" for
		the purposes of refusing to send error returns.  Suggested
		by Motonori Nakamura of Ritsumeikan University.
	Relax rules on when a file can be written when referenced from
		the aliases file: use the default uid/gid instead of the
		real uid/gid.  This allows you to create a file owned by
		and writable only by the default uid/gid that will work
		all the time (without having the setuid bit set).  Change
		suggested by Shau-Ping Lo and Andrew Cheng of Sun
		Microsystems.
	Add "DialDelay" option (no short name) to provide an "extra"
		delay for dial on demand systems.  If this is non-zero
		and a connect fails, sendmail will wait this long and
		then try again.  If it takes longer than the kernel
		timeout interval to establish the connection, this
		option can give the network software time to establish
		the link.  The default units are seconds.
	Move logging of sender information to be as early as possible;
		previously, it could be delayed a while for SMTP mail
		sent to aliases.  Suggested by Brad Knowles of the
		Defense Information Systems Agency.
	Call res_init() before setting RES_DEBUG; this is required by
		BIND 4.9.3, or so I'm told.  From Douglas Anderson of
		the National Computer Security Center.
	Add xdelay= field in logs -- this is a transaction delay, telling
		you how long it took to deliver to this address on the
		last try.  It is intended to be used for sorting mailing
		lists to favor "quick" addresses.  Provided for use by
		the mailprio scripts (see below).
	If a map cannot be opened, and that map is non-optional, and
		an address requires that map for resolution, queue the
		map instead of bouncing it.  This involves creating a
		pseudo-class of maps called "bogus-map" -- if a required
		map cannot be opened, the class is changed to bogus-map;
		all queries against bogus-map return "tempfail".  The
		bogus-map class is not directly accessible.  A sample
		implementation was donated by Jem Taylor of Glasgow
		University Computing Service.
	Don't make a bad ``MAIL FROM:'' address on one message blow away
		other messages to the same host later in the queue.
		Problem noted by Eric Prestemon of American University.
	Fix a possible core dump when mailing to a program that talks
		SMTP on its standard input.  Fix from Keith Moore of
		the University of Kentucky.
	Make it possible to resolve filenames to $#local $: @ /filename;
		previously, the "@" would cause it to not be recognized
		as a file.  Problem noted by Brian Hill of U.C. Davis.
	Accept a -1 signal to re-exec the daemon.  This only works if
		argv[0] is a full path to sendmail.
	Fix bug in "addr=..." field in O option on little-endian machines
		-- the network number wasn't being converted to network
		byte order.  Patch from Kurt Lidl of Pix Technologies
		Corporation.
	Pre-initialize the resolver early on; this is to avoid a bug with
		BIND 4.9.3 that can cause the _res.retry field to get
		reset to zero, causing all name server lookups to time
		out.  Fix from Matt Day of Artisoft.
	Restore T line (trusted users) in config file -- but instead of
		locking out the -f flag, they just tell whether or not
		an X-Authentication-Warning: will be added.  This really
		just creates new entries in class 't', so "Ft/file/name"
		can be used to read trusted user names from a file.
	Improve NEWDB alias file rebuilding so it will create them
		properly if they do not already exist.  This had been
		a MAYBENEXTRELEASE feature in 8.6.9.
	Check for @:@ entry in NIS maps before starting up to avoid
		(but not prevent, sigh) race conditions.  This ought to
		be handled properly in ypserv, but isn't.  Suggested by
		Michael Beirne of Motorola.
	Refuse connections if there isn't enough space on the filesystem
		holding the queue.  Contributed by Robert Dana of Wolf
		Communications.
	Skip checking for directory permissions in the path to a file
		when checking for file permissions iff setreuid()
		succeeded -- it is unnecessary in that case.  This avoids
		significant performance problems when looking for .forward
		files.  Based on a suggestion by Win Bent of USC.
	Allow symbolic ruleset names.  Syntax can be "Sname" to get an
		arbitrary ruleset number assigned or "Sname = integer"
		to assign a specific ruleset number.  Reference is
		$>name_or_number.  Names can be composed of alphas, digits,
		underscore, or hyphen (first character must be non-numeric).
	Allow -o flag on AliasFile lines to make the alias file optional.
		From Bryan Costales of ICSI.
	Add NoRecipientAction option to handle the case where there is
		no legal recipient header in the message.  It can take
		on values:
		  None			Leave the message as is.  The
					message will be passed on even
					though it is in technically
					illegal syntax.
		  Add-To		Add a To: header with any
					recipients that it can find from
					the envelope.  This risks exposing
					Bcc: recipients.
		  Add-Apparently-To	Add an Apparently-To: header.  This
					has almost no redeeming social value,
					and is provided only for back
					compatibility.
		  Add-To-Undisclosed	Add a header reading
					To: undisclosed-recipients:;
					which will have the effect of
					making the message legal without
					exposing Bcc: recipients.
		  Add-Bcc		To add an empty Bcc: header.
					There is a chance that mailers down
					the line will delete this header,
					which could cause exposure of Bcc:
					recipients.
		The default is NoRecipientAction=None.
	Truncate (rather than delete) Bcc: lines in the header.  This
		should prevent later sendmails (at least, those that don't
		themselves delete Bcc:) from considering this message to
		be non-conforming -- although it does imply that non-blind
		recipients can see that a Bcc: was sent, albeit not to whom.
	Add SafeFileEnvironment option.  If declared, files named as delivery
		targets must be regular files in addition to the regular
		checks.  Also, if the option is non-null then it is used as
		the name of a directory that is used as a chroot(2)
		environment for the delivery; the file names listed in an
		alias or forward should include the name of this root.
		For example, if you run with
			O SafeFileEnvironment=/arch
		then aliases should reference "/arch/rest/of/path".  If a
		value is given, sendmail also won't try to save to
		/usr/tmp/dead.letter (instead it just leaves the job in the
		queue as Qfxxxxxx).  Inspired by *Hobbit*'s sendmail patch kit.
	Support -A flag for alias files; this will comma concatenate like
		entries.  For example, given the aliases:
			list: member1
			list: member2
		and an alias file declared as:
			OAhash:-A /etc/aliases
		the final alias inserted will be "list: member1,member2";
		without -A you will get an error on the second and subsequent
		alias for "list".  Contributed by Bryan Costales of ICSI.
	Line-buffer transcript file.  Suggested by Liudvikas Bukys.
	Fix a problem that could cause very long addresses to core dump in
		some special circumstances.  Problem pointed out by Allan
		Johannesen.
	(Internal change.)  Change interface to expand() (macro expansion)
		to be simpler and more consistent.
	Delete check for funny qf file names.  This didn't really give
		any extra security and caused some people some problems.
		(If you -really- want this, define PICKY_QF_NAME_CHECK
		at compile time.)  Suggested by Kyle Jones of UUNET.
	(Internal change.)  Change EF_NORETURN to EF_NO_BODY_RETN and
		merge with DSN code; this is simpler and more consistent.
		This may affect some people who have written their own
		checkcompat() routine.
	(Internal change.)  Eliminate `D' line in qf file.  The df file
		is now assumed to be the same name as the qf file (with
		the `q' changed to a `d', of course).
	Avoid forking for delivery if all recipient mailers are marked as
		"expensive" -- this can be a major cost on some systems.
		Essentially, this forces sendmail into "queue only" mode
		if all it is going to do is queue anyway.
	Avoid sending a null message in some rather unusual circumstances
		(specifically, the RCPT command returns a temporary
		failure but the connection is lost before the DATA
		command).  Fix from Scott Hammond of Secure Computing
		Corporation.
	Change makesendmail to use a somewhat more rational naming scheme:
		Makefiles and obj directories are named $os.$rel.$arch,
		where $os is the operating system (e.g., SunOS), $rel is
		the release number (e.g., 5.3), and $arch is the machine
		architecture (e.g., sun4).  Any of these can be omitted,
		and anything after the first dot in a release number can
		be replaced with "x" (e.g., SunOS.4.x.sun4).  The previous
		version used $os.$arch.$rel and was rather less general.
	Ignore IDENT return value if the OSTYPE field returns "OTHER",
		as indicated by RFC 1413.  Pointed out by Kari Hurtta
		of the Finnish Meteorological Institute.
	Fix problem that could cause multiple responses to DATA command
		on header syntax errors (e.g., lines beginning with colons).
		Problem noted by Jens Thomassen of the University of Oslo.
	Don't let null bytes in headers cause truncation of the rest of
		the header.
	Log Authentication-Warning:s.  Suggested by Motonori Nakamura.
	Increase timeouts on message data puts to allow time for receivers
		to canonify addresses in headers on the fly.  This is still
		a rather ugly heuristic.  From Motonori Nakamura.
	Add "HasWildcardMX" suboption to ResolverOptions; if set, MX
		records are not used when canonifying names.  This is
		useful if you have a wildcard MX record, although it
		may cause other problems.  In general, don't use wildcard
		MX records.  Patch from Motonori Nakamura.
	Eliminate default two-line SMTP greeting message.  Instead of
		adding an extra "ESMTP spoken here" line, the word "ESMTP"
		is added between the first and second word of the first
		line of the greeting message (i.e., immediately after the
		host name).  This eliminates the need for the BROKEN_SMTP_PEERS
		compile flag.  Old sendmails won't see the ESMTP, but that's
		acceptable because SIZE was the only useful extension that
		old sendmails understand.
	Avoid gethostbyname calls on UNIX domain sockets during SIGUSR1
		invoked state dumps.  From Masaharu Onishi.
	Allow on-line comments in .forward and :include: files; they are
		introduced by the string "<LWSP>#@#<LWSP>", where <LWSP>
		is a space or a tab.  This is intended for native
		representation of non-ASCII sets such as Japanese, where
		existing encodings would be unreadable or would lose
		data -- for example,
		 <motonori@cs.ritsumei.ac.jp> NAKAMURA Motonori
					(romanized/less information)
		 <motonori@cs.ritsumei.ac.jp> =?ISO-2022-JP?B?GyRCQ2ZCPBsoQg==?=
					      =?ISO-2022-JP?B?GyRCQUdFNRsoQg==?=
					(with MIME encoding, not human readable)
		 <motonori@cs.ritsumei.ac.jp> #@# ^[$BCfB<^[(B ^[$BAGE5^[(B
					(native encoding with ISO-2022-JP)
		The last form is human readable in the Japanese environment.
		Based on a fix from (surprise!) Motonori Nakamura.
	Don't make SMTP error returns on MAIL FROM: line be "sticky" for all
		messages to that host; these are most frequently associated
		with addresses rather than the host, with the exception of
		421 (service shutting down).  The effect was to cause queues
		to sometimes take an excessive time to flush.  Reported by
		Robert Sargent of Southern Geographics Technologies.
	Add Nice=N mailer option to set the niceness at which a mailer will
		run.
	When looking for a default config file (that is, not specified using
		a -C flag), try a configuration file name extended by the
		binary version number -- e.g., sendmail.8.7.Alpha.9.cf,
		sendmail.8.7.Alpha.cf, sendmail.8.7.cf, sendmail.8.cf, and
		sendmail.cf in that order.  This should make it easier to
		test new versions in a shared environment.
	Log queue runs that are skipped due to high loads.  They are logged
		at LOG_INFO priority iff the log level is > 8.  Contributed
		by Bruce Nagel of Data General.
	Allow the error mailer to accept a DSN-style error status code
		instead of an sysexits status code in the host part.
		Anything with a dot will be interpreted as a DSN-style code.
	Add new mailer flag: F=3 will tell translations to Quoted-Printable
		to encode characters that might be munged by an EBCDIC system
		in addition to the set required by RFC 1521.  The additional
		characters are !, ", #, $, @, [, \, ], ^, `, {, |, }, and ~.
		(Think of "IBM 360" as the mnemonic for this flag.)
	Change check for mailing to files to look for a pathname of [FILE]
		rather than looking for the mailer named *file*.  The mapping
		of leading slashes still goes to the *file* mailer.  This
		allows you to implement the *file* mailer as a separate
		program, for example, to insert a Content-Length: header
		or do special security policy.  However, note that the usual
		initial checking for the file permissions is still done, and
		the program in question needs to be very careful about how
		it does the file write to avoid security problems.
	Be able to read ~root/.forward even if the path isn't accessible to
		regular users.  This is disrecommended because sendmail
		sometimes does not run as root (e.g., when an unsafe option
		is specified on the command line), but should otherwise be
		safe because .forward files must be owned by the user for
		whom mail is being forwarded, and cannot be a symbolic link.
		Suggested by Forrest Aldrich of Wang Laboratories.
	Add new "HostsFile" option that is the pathname to the /etc/hosts
		file.  This is used for canonifying hostnames when the
		service type is "files".
	Implement programs on F (read class from file) line.  The syntax is
		Fc|/path/to/program to read the output from the program
		into class "c".
	Probe the network interfaces to find alternate names for this
		host.  Requires the SIOCGIFCONF ioctl call.  Code
		contributed by SunSoft.
	Add "E" configuration line to set or propogate environment
		variables into children.  "E<envar>" will propogate
		the named variable from the environment when sendmail
		was invoked into any children it calls; "E<envar>=<value>"
		sets the named variable to the indicated value.  Any
		variables not explicitly named will not be in the child
		environment.  However, sendmail still forces an
		"AGENT=sendmail" environment variable, in part to enforce
		at least one environment variable, since many programs and
		libraries die horribly if this is not guaranteed.
	PORTABILITY FIXES:
		Solaris 2 from Rob McMahon <cudcv@csv.warwick.ac.uk>.
		System V Release 4 from Motonori Nakamura of Ritsumeikan
			University.  This expands the disk size
			checking to include all (?) SVR4 configurations.
		System V Release 4 from Kimmo Suominen -- initgroups(3)
			and setrlimit(2) are both available.
		System V Release 4 from sob@sculley.ffg.com -- some versions
			apparently "have EX_OK defined in other headerfiles."
		Linux Makefile typo.
		Linux getusershell(3) is broken in Slackware 2.0 --
			from Andrew Pam of Xanadu Australia.
		More Linux tweaking from John Kennedy of California State
			University, Chico.
		Cray changes from Eric Wassenaar:  ``On Cray, shorts,
			ints, and longs are all 64 bits, and all structs
			are multiples of 64 bits.  This means that the
			sizeof operator returns only multiples of 8.
			This requires adaptation of code that really
			deals with 32 bit or 16 bit fields, such as IP
			addresses or nameserver fields.''
		DG/UX 5.4.3 from Mark T. Robinson <mtr@ornl.gov>.  To
			get the old behaviour, use -DDGUX_5_4_2.
		DG/UX hack: add _FORCE_MAIL_LOCAL_=yes environment
			variable to fix bogus /bin/mail behaviour.
		Tandem NonStop-UX from Rick McCarty <mccarty@mpd.tandem.com>.
			This also cleans up some System V Release 4 compile
			problems.
		Solaris 2: sendmail.cw file should be in /etc/mail to
			match all the other configuration files.  Fix
			from Glenn Barry of Emory University.
		Solaris 2.3: compile problem in conf.c.  Fix from Alain
			Nissen of the University of Liege, Belgium.
		Ultrix: freespace calculation was incorrect.  Fix from
			Takashi Kizu of Osaka University.
		SVR4: running in background gets a SIGTTOU because the
			emulation code doesn't realize that "getpeername"
			doesn't require reading the file.  Fix from Peter
			Wemm of DIALix.
		Solaris 2.3: due to an apparent bug in the socket emulation
			library, sockets can get into a "wedged" state where
			they just return EPROTO; closing and re-opening the
			socket clears the problem.  Fix from Bob Manson
			of Ohio State University.
		Hitachi 3050R & 3050RX running HI-UX/WE2: portability
			fixes from Akihiro Hashimoto ("Hash") of Chiba
			University.