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CACerts15-Jul-20205.4 KiB

cf/15-Jul-202013

contrib/15-Jul-202030

doc/06-Nov-20123

editmap/15-Jul-20206

FAQ13-Jul-2015172

FREEBSD-upgrade15-Jul-20203 KiB

include/06-Nov-20126

INSTALL13-Jul-20152 KiB

KNOWNBUGS15-Jul-202011.4 KiB

libmilter/15-Jul-202018

libsm/15-Jul-2020113

libsmdb/15-Jul-20209

libsmutil/15-Jul-202010

LICENSE15-Jul-20204.1 KiB

mail.local/15-Jul-20207

mailstats/15-Jul-20206

Makefile22-May-2014966

makemap/15-Jul-20206

PGPKEYS15-Jul-2020223.8 KiB

praliases/15-Jul-20206

README15-Jul-202017.2 KiB

RELEASE_NOTES15-Jul-2020535.6 KiB

rmail/15-Jul-20206

smrsh/15-Jul-20207

src/15-Jul-202066

test/15-Jul-202014

vacation/15-Jul-20206

README

1
2			SENDMAIL RELEASE 8
3
4This directory has the latest sendmail(TM) software from Proofpoint, Inc.
5
6Report any bugs to sendmail-bugs-YYYY@support.sendmail.org
7where YYYY is the current year, e.g., 2005.
8
9There is a web site at http://www.sendmail.org/ -- see that site for
10the latest updates.
11
12+--------------+
13| INTRODUCTION |
14+--------------+
15
160. The vast majority of queries about sendmail are answered in the
17   README files noted below.
18
191. Read this README file, especially this introduction, and the DIRECTORY
20   PERMISSIONS sections.
21
222. Read the INSTALL file in this directory.
23
243. Read sendmail/README, especially:
25   a. the introduction
26   b. the BUILDING SENDMAIL section
27   c. the relevant part(s) of the OPERATING SYSTEM AND COMPILE QUIRKS section
28
29   You may also find these useful:
30
31   d. sendmail/SECURITY
32   e. devtools/README
33   f. devtools/Site/README
34   g. libmilter/README
35   h. mail.local/README
36   i. smrsh/README
37
384. Read cf/README.
39
40Sendmail is a trademark of Proofpoint, Inc.
41US Patent Numbers 6865671, 6986037.
42
43+-----------------------+
44| DIRECTORY PERMISSIONS |
45+-----------------------+
46
47Sendmail often gets blamed for many problems that are actually the
48result of other problems, such as overly permissive modes on directories.
49For this reason, sendmail checks the modes on system directories and
50files to determine if they can be trusted.  For sendmail to run without
51complaining, you MUST execute the following command:
52
53	chmod go-w / /etc /etc/mail /usr /var /var/spool /var/spool/mqueue
54	chown root / /etc /etc/mail /usr /var /var/spool /var/spool/mqueue
55
56You will probably have to tweak this for your environment (for example,
57some systems put the spool directory into /usr/spool instead of
58/var/spool).  If you set the RunAsUser option in your sendmail.cf, the
59/var/spool/mqueue directory will have to be owned by the RunAsUser user.
60As a general rule, after you have compiled sendmail, run the command
61
62	sendmail -v -bi
63
64to initialize the alias database.  If it gives messages such as
65
66	WARNING: writable directory /etc
67	WARNING: writable directory /var/spool/mqueue
68
69then the directories listed have inappropriate write permissions and
70should be secured to avoid various possible security attacks.
71
72Beginning with sendmail 8.9, these checks have become more strict to
73prevent users from being able to access files they would normally not
74be able to read.  In particular, .forward and :include: files in unsafe
75directory paths (directory paths which are group or world writable) will
76no longer be allowed.  This would mean that if user joe's home directory
77was writable by group staff, sendmail would not use his .forward file.
78This behavior can be altered, at the expense of system security, by
79setting the DontBlameSendmail option.  For example, to allow .forward
80files in group writable directories:
81
82	O DontBlameSendmail=forwardfileingroupwritabledirpath
83
84Or to allow them in both group and world writable directories:
85
86	O DontBlameSendmail=forwardfileinunsafedirpath
87
88Items from these unsafe .forward and :include: files will be marked
89as unsafe addresses -- the items can not be deliveries to files or
90programs.  This behavior can also be altered via DontBlameSendmail:
91
92	O DontBlameSendmail=forwardfileinunsafedirpath,
93		forwardfileinunsafedirpathsafe
94
95The first flag allows the .forward file to be read, the second allows
96the items in the file to be marked as safe for file and program
97delivery.
98
99Other files affected by this strengthened security include class
100files (i.e., Fw /etc/mail/local-host-names), persistent host status files,
101and the files specified by the ErrorHeader and HelpFile options.  Similar
102DontBlameSendmail flags are available for the class, ErrorHeader, and
103HelpFile files.
104
105If you have an unsafe configuration of .forward and :include:
106files, you can make it safe by finding all such files, and doing
107a "chmod go-w $FILE" on each.  Also, do a "chmod go-w $DIR" for
108each directory in the file's path.
109
110
111+--------------------------+
112| FILE AND MAP PERMISSIONS |
113+--------------------------+
114
115Any application which uses either flock() or fcntl() style locking or
116other APIs that use one of these locking methods (such as open() with
117O_EXLOCK and O_SHLOCK) on files readable by other local untrusted users
118may be susceptible to local denial of service attacks.
119
120File locking is used throughout sendmail for a variety of files
121including aliases, maps, statistics, and the pid file.  Any user who
122can open one of these files can prevent sendmail or it's associated
123utilities, e.g., makemap or newaliases, from operating properly.  This
124can also affect sendmail's ability to update status files such as
125statistics files.  For system which use flock() for file locking, a
126user's ability to obtain an exclusive lock prevents other sendmail
127processes from reading certain files such as alias or map databases.
128
129A workaround for this problem is to protect all sendmail files such
130that they can't be opened by untrusted users.  As long as users can
131not open a file, they can not lock it.  Since queue files should
132already have restricted permissions, the only files that need
133adjustment are alias, map, statistics, and pid files.  These files
134should be owned by root or the trusted user specified in the
135TrustedUser option.  Changing the permissions to be only readable and
136writable by that user is sufficient to avoid the denial of service.
137For example, depending on the paths you use, these commands would be
138used:
139
140	chmod 0640 /etc/mail/aliases /etc/mail/aliases.{db,pag,dir}
141	chmod 0640 /etc/mail/*.{db,pag,dir}
142	chmod 0640 /etc/mail/statistics /var/log/sendmail.st
143	chmod 0600 /var/run/sendmail.pid /etc/mail/sendmail.pid
144
145If the permissions 0640 are used, be sure that only trusted users belong
146to the group assigned to those files.  Otherwise, files should not even
147be group readable.  As of sendmail 8.12.4, the permissions shown above
148are the default permissions for newly created files.
149
150Note that the denial of service on the plain text aliases file
151(/etc/mail/aliases) only prevents newaliases from rebuilding the
152aliases file.  The same is true for the database files on systems which
153use fcntl() style locking.  Since it does not interfere with normal
154operations, sites may chose to leave these files readable.  Also, it is
155not necessary to protect the text files associated with map databases
156as makemap does not lock those files.
157
158
159+-----------------------+
160| RELATED DOCUMENTATION |
161+-----------------------+
162
163There are other files you should read.  Rooted in this directory are:
164
165  FAQ
166	The FAQ (frequently answered questions) is no longer maintained
167	with the sendmail release.  It is available at
168	http://www.sendmail.org/faq/ .  The file FAQ is a reminder of
169	this and a pointer to the web page.
170  INSTALL
171	Installation instructions for building and installing sendmail.
172  KNOWNBUGS
173	Known bugs in the current release.
174  RELEASE_NOTES
175	A detailed description of the changes in each version.  This
176	is quite long, but informative.
177  sendmail/README
178	Details on compiling and installing sendmail.
179  cf/README
180	Details on configuring sendmail.
181  doc/op/op.me
182	The sendmail Installation & Operations Guide.  In addition
183	to the shipped PostScript version, plain text and PDF versions
184	can be generating using (assuming the required conversion software
185	is installed on your system, see doc/op/Makefile):
186
187	cd doc/op && make op.txt op.pdf
188
189	Be warned: on some systems calling make in doc/op/ will cause
190	errors due to nroff/groff problems.  Known problems are:
191	- running this off on systems with an old version of -me, you
192	need to add the following macro to the macros:
193
194		.de sm
195		\s-1\\$1\\s0\\$2
196		..
197
198	This sets a word in a smaller pointsize.
199
200	- with new groff versions (1.18 seems affected)
201
202	GROFF_NO_SGR=1
203
204	needs to be set, e.g., in doc/op/Makefile:
205
206	ROFF_CMD=	GROFF_NO_SGR=1 groff
207
208
209+--------------+
210| RELATED RFCS |
211+--------------+
212
213There are several related RFCs that you may wish to read -- they are
214available from several sites, see
215
216	http://www.rfc-editor.org/
217	http://www.ietf.org/
218
219Important RFCs for electronic mail are:
220
221	RFC821	SMTP protocol
222	RFC822	Mail header format
223	RFC974	MX routing
224	RFC976	UUCP mail format
225	RFC1123	Host requirements (modifies 821, 822, and 974)
226	RFC1344	Implications of MIME for Internet Mail Gateways
227	RFC1413	Identification server
228	RFC1428	Transition of Internet Mail from Just-Send-8 to
229		8-bit SMTP/MIME
230	RFC1652	SMTP Service Extension for 8bit-MIMEtransport
231	RFC1869	SMTP Service Extensions (ESMTP spec)
232	RFC1870	SMTP Service Extension for Message Size Declaration
233	RFC1891	SMTP Service Extension for Delivery Status Notifications
234	RFC1892	Multipart/Report Content Type for the Reporting of
235		Mail System Administrative Messages
236	RFC1893	Enhanced Mail System Status Codes
237	RFC1894	An Extensible Message Format for Delivery Status
238		Notifications
239	RFC1985	SMTP Service Extension for Remote Message Queue Starting
240	RFC2033 Local Mail Transfer Protocol (LMTP)
241	RFC2034 SMTP Service Extension for Returning Enhanced Error Codes
242	RFC2045	Multipurpose Internet Mail Extensions (MIME) Part One:
243		Format of Internet Message Bodies
244	RFC2476 Message Submission
245	RFC2487 SMTP Service Extension for Secure SMTP over TLS
246	RFC2554 SMTP Service Extension for Authentication
247	RFC2821 Simple Mail Transfer Protocol
248	RFC2822 Internet Message Format
249	RFC2852 Deliver By SMTP Service Extension
250	RFC2920 SMTP Service Extension for Command Pipelining
251
252Other standards that may be of interest (but which are less directly
253relevant to sendmail) are:
254
255	RFC987	Mapping between RFC822 and X.400
256	RFC1049	Content-Type header field (extension to RFC822)
257
258Warning to AIX users: this version of sendmail does not implement
259MB, MR, or MG DNS resource records, as defined (as experiments) in
260RFC1035.
261
262
263+---------+
264| WARNING |
265+---------+
266
267Since sendmail 8.11 and later includes hooks to cryptography, the
268following information from OpenSSL applies to sendmail as well.
269
270PLEASE REMEMBER THAT EXPORT/IMPORT AND/OR USE OF STRONG CRYPTOGRAPHY
271SOFTWARE, PROVIDING CRYPTOGRAPHY HOOKS OR EVEN JUST COMMUNICATING
272TECHNICAL DETAILS ABOUT CRYPTOGRAPHY SOFTWARE IS ILLEGAL IN SOME
273PARTS OF THE WORLD.  SO, WHEN YOU IMPORT THIS PACKAGE TO YOUR
274COUNTRY, RE-DISTRIBUTE IT FROM THERE OR EVEN JUST EMAIL TECHNICAL
275SUGGESTIONS OR EVEN SOURCE PATCHES TO THE AUTHOR OR OTHER PEOPLE
276YOU ARE STRONGLY ADVISED TO PAY CLOSE ATTENTION TO ANY EXPORT/IMPORT
277AND/OR USE LAWS WHICH APPLY TO YOU.  THE AUTHORS ARE NOT LIABLE FOR
278ANY VIOLATIONS YOU MAKE HERE.  SO BE CAREFUL, IT IS YOUR RESPONSIBILITY.
279
280If you use OpenSSL then make sure you read their README file which
281contains information about patents etc.
282
283
284+-------------------+
285| DATABASE ROUTINES |
286+-------------------+
287
288IF YOU WANT TO RUN THE NEW BERKELEY DB SOFTWARE:  ****  DO NOT  ****
289use the version that was on the Net2 tape -- it has a number of
290nefarious bugs that were bad enough when I got them; you shouldn't have
291to go through the same thing.  Instead, get a new version via the web at
292http://www.sleepycat.com/.  This software is highly recommended; it gets
293rid of several stupid limits, it's much faster, and the interface is
294nicer to animals and plants.  If the Berkeley DB include files
295are installed in a location other than those which your compiler searches,
296you will need to provide that directory when building:
297
298	./Build -I/path/to/include/directory
299
300If you are using Berkeley DB versions 1.85 or 1.86, you are *strongly*
301urged to upgrade to DB version 2 or later, available from
302http://www.sleepycat.com/.  Berkeley DB versions 1.85 and 1.86 are known to
303be broken in various nasty ways (see http://www.sleepycat.com/db.185.html),
304and can cause sendmail to dump core.  In addition, the newest versions of
305gcc and the Solaris compilers perform optimizations in those versions that
306may cause fairly random core dumps.
307
308If you have no choice but to use Berkeley DB 1.85 or 1.86, and you are
309using both Berkeley DB and files in the UNIX ndbm format, remove ndbm.h
310and ndbm.o from the DB library after building it.  You should also apply
311all of the patches for DB 1.85 and 1.86 found at the Sleepycat web site
312(see http://www.sleepycat.com/db.185.html), as they fix some of the known
313problems.
314
315If you are using a version of Berkeley DB 2 previous to 2.3.15, and you
316are using both Berkeley DB and files in the UNIX ndbm format, remove dbm.o
317from the DB library after building it.  No other changes are necessary.
318
319If you are using Berkeley DB version 2.3.15 or greater, no changes are
320necessary.
321
322The underlying database file formats changed between Berkeley DB versions
3231.85 and 1.86, again between DB 1.86 and version 2.0, and finally between
324DB 2.X and 3.X.  If you are upgrading from one of those versions, you must
325recreate your database file(s).  Do this by rebuilding all maps with
326makemap and rebuilding the alias file with newaliases.
327
328
329+--------------------+
330| HOST NAME SERVICES |
331+--------------------+
332
333If you are using NIS or /etc/hosts, it is critical that you
334list the long (fully qualified) name somewhere (preferably first) in
335the /etc/hosts file used to build the NIS database.  For example, the
336line should read
337
338	128.32.149.68   mastodon.CS.Berkeley.EDU mastodon
339
340**** NOT ****
341
342	128.32.149.68   mastodon
343
344If you do not include the long name, sendmail will complain loudly
345about ``unable to qualify my own domain name (mastodon) -- using
346short name'' and conclude that your canonical name is the short
347version and use that in messages.  The name "mastodon" doesn't mean
348much outside of Berkeley, and so this creates incorrect and unreplyable
349messages.
350
351
352+-------------+
353| USE WITH MH |
354+-------------+
355
356This version of sendmail notices and reports certain kinds of SMTP
357protocol violations that were ignored by older versions.  If you
358are running MH you may wish to install the patch in contrib/mh.patch
359that will prevent these warning reports.  This patch also works
360with the old version of sendmail, so it's safe to go ahead and
361install it.
362
363
364+----------------+
365| USE WITH IDENT |
366+----------------+
367
368Sendmail 8 supports the IDENT protocol, as defined by RFC 1413.
369Note that the RFC states a client should wait at least 30 seconds
370for a response.  As of 8.10.0, the default Timeout.ident is 5 seconds
371as many sites have adopted the practice of dropping IDENT queries.
372This has lead to delays processing mail.
373
374No ident server is included with this distribution.  It is available
375from:
376
377  ftp://ftp.lysator.liu.se/pub/ident/servers/
378  http://sf.www.lysator.liu.se/~pen/pidentd/
379
380+-------------------------+
381| INTEROPERATION PROBLEMS |
382+-------------------------+
383
384Microsoft Exchange Server 5.0
385	We have had a report that ``about 7% of messages from Sendmail
386	to Exchange were not being delivered with status messages of
387	"connection reset" and "I/O error".''  Upgrading Exchange from
388	Version 5.0 to Version 5.5 Service Pack 2 solved this problem.
389
390CommuniGate Pro
391	CommuniGate Pro 3.2.4 does not accept the AUTH= -parameter on
392	the MAIL FROM command if the client is not authenticated.  Use
393
394		define(`confAUTH_OPTIONS', `A')
395
396	in .mc file if you have compiled sendmail with Cyrus SASL
397	and you communicate with CommuniGate Pro servers.
398
399+---------------------+
400| DIRECTORY STRUCTURE |
401+---------------------+
402
403The structure of this directory tree is:
404
405cf		Source for sendmail configuration files.  These are
406		different than what you've seen before.  They are a
407		fairly dramatic rewrite, requiring the new sendmail
408		(since they use new features).
409contrib		Some contributed tools to help with sendmail.  THESE
410		ARE NOT SUPPORTED by sendmail -- contact the original
411		authors if you have problems.  (This directory is not
412		on the 4.4BSD tape.)
413devtools	Build environment.  See devtools/README.
414doc		Documentation.  If you are getting source, read
415		op.me -- it's long, but worth it.
416editmap		A program to edit and query maps that have been created
417		with makemap, e.g., adding and deleting entries.
418include		Include files used by multiple programs in the distribution.
419libsmdb		sendmail database library with support for Berkeley DB 1.X,
420		Berkeley DB 2.X, Berkeley DB 3.X, and NDBM.
421libsmutil	sendmail utility library with functions used by different
422		programs.
423mail.local	The source for the local delivery agent used for 4.4BSD.
424		THIS IS NOT PART OF SENDMAIL! and may not compile
425		everywhere, since it depends on some 4.4-isms.  Warning:
426		it does mailbox locking differently than other systems.
427mailstats	Statistics printing program.
428makemap		A program that creates the keyed maps used by the $( ... $)
429		construct in sendmail.  It is primitive but effective.
430		It takes a very simple input format, so you will probably
431		expect to preprocess must human-convenient formats
432		using sed scripts before this program will like them.
433		But it should be functionally complete.
434praliases	A program to print the map version of the aliases file.
435rmail		Source for rmail(8).  This is used as a delivery
436		agent for for UUCP, and could presumably be used by
437		other non-socket oriented mailers.  Older versions of
438		rmail are probably deficient.  RMAIL IS NOT PART OF
439		SENDMAIL!!!  The 4.4BSD source is included for you to
440		look at or try to port to your system.  There is no
441		guarantee it will even compile on your operating system.
442smrsh		The "sendmail restricted shell", which can be used as
443		a replacement for /bin/sh in the prog mailer to provide
444		increased security control.  NOT PART OF SENDMAIL!
445sendmail	Source for the sendmail program itself.
446test		Some test scripts (currently only for compilation aids).
447vacation	Source for the vacation program.  NOT PART OF SENDMAIL!
448
449