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sendmail(8)							   sendmail(8)

       sendmail, newaliases, mailq, smtpd - Sends mail over the Internet

       /usr/sbin/sendmail [options] [address...]


       /usr/sbin/mailq [-v]


       Set  the	 body type to type. The current values are 7BIT or 8BITMIME ..
       Goes into ARPANET mode. All input lines must end with a CR-LF, and  all
       messages will be generated with a CR-LF at the end. Also, the From: and
       Sender: fields are examined for the name of the sender.	Runs as a dae‐
       mon.   This  requires  Berkeley	Interprocess Communications (IPC). The
       sendmail command will fork and run in the background, listening on  the
       socket  specified  in  the /etc/services file for incoming SMTP (Simple
       Mail Transfer Protocol) connections.  This is normally run  when	 going
       to multiuser mode.

	      Using  this  option is equivalent to invoking sendmail as smtpd.
	      Initializes the alias database.  This is the  same  as  invoking
	      the   newaliases	command.   Delivers  mail  in  the  usual  way
	      (default).  Prints a listing of the queue.  This is the same  as
	      invoking	the mailq command.  Use the SMTP protocol as described
	      in RFC821 on standard input and output. This option implies  all
	      the  operations of the -ba option that are compatible with SMTP.
	      Runs in address test mode.  This mode reads addresses and	 shows
	      the  steps  in  parsing;	it is used for debugging configuration
	      tables.  Verifies names  only.   Does  not  try  to  collect  or
	      deliver  a  message. Verify mode is normally used for validating
	      users or mailing lists.  Uses alternate configuration file.  The
	      sendmail command refuses to run as root if an alternate configu‐
	      ration file is specified.	 Sets debugging value to X.  A	useful
	      value  is	 21.n,	where  n is any nonzero integer less than 100.
	      This produces information regarding address parsing and is typi‐
	      cally used with the -bt option.  Higher values of n produce more
	      verbose information.  Sets the full name of  the	sender.	  Sets
	      the  name	 of  the  From: user field (that is, the sender of the
	      mail). The -f option can only be used by trusted users (normally
	      root,  daemon,  and  network) or if the person you are trying to
	      become is the same as the person you are.	 Sets the hop count to
	      N.   The	hop  count  is incremented every time the mail is pro‐
	      cessed.  When it reaches a limit, the mail is returned  with  an
	      error message, the victim of an aliasing loop. If not specified,
	      Received lines in the message are counted. The maximum hop count
	      is  configurable,	 but defaults to 30 if you do not configure an
	      alternate value.	 The  default  value  is  acceptable  in  most
	      installations but you may want to increase the value if too many
	      messages are being lost Defines Macro to have Value. This option
	      is  normally  used  only	from the sendmail daemon command line.
	      Does not do aliasing or forwarding.  Sets option to  the	speci‐
	      fied  value.   This  form	 uses  long names.  Processing options
	      specified with -O are described in the Sendmail Installation and
	      Operation	 Guide	on the Documentation CD-ROM.  Sets option X to
	      the specified value.  Processing options specified with  -o  are
	      described	 in  the  Sendmail Processing Options section later in
	      this reference page.  Set the  name  of  the  protocol  used  to
	      receive  the message. This can be a simple protocol name such as
	      UUCP or a protocol and hostname, such as UUCP:ucbvax.  Processes
	      saved  messages  in  the	queue  at given intervals.  If time is
	      omitted, processes the queue once. The time command is given  as
	      a	 tagged number, with s being seconds, m being minutes, h being
	      hours, d being days, and w being weeks.  For example, -q1h30m or
	      -q90m  would both set the time-out to 1 hour and 30 minutes.  If
	      the time command is specified, the sendmail command will run  in
	      background  mode.	  This	option	can  be	 used safely with -bd.
	      Limit processed jobs to those containing substr as  a  substring
	      of  the queue ID.	 Limit processed jobs to those containing sub‐
	      str as a substring of one of the	recipients.   Limit  processed
	      jobs  to	those  containing substr as a substring of the sender.
	      An alternate and obsolete form of the -f option.	Reads  a  mes‐
	      sage  for	 recipients.   The  To:,  Cc:,	and Bcc: lines will be
	      scanned for recipient addresses. The Bcc: line will  be  deleted
	      before  transmission. Any addresses in the argument list will be
	      suppressed; that is, they will not receive copies even if listed
	      in  the  message	header.	 Goes into verbose mode.  Alias expan‐
	      sions will be announced, and so forth.  Log all traffic  in  and
	      out  of  mailers	in the indicated log file. This should only be
	      used as a last resort for debugging mailer bugs. It will	log  a
	      lot of data very quickly.

       Specifes the mail recipient. You can specify more than one address.

       The sendmail command sends a message to one or more recipients, routing
       the message over whatever networks are necessary.  The sendmail command
       does internetwork forwarding as necessary to deliver the message to the
       correct place.

       The sendmail command is not intended as a user interface routine. Other
       programs	 provide  user-friendly	 front	ends; sendmail is used only to
       deliver preformatted messages.

       With no options, sendmail reads its standard input up to an End-of-File
       or to a line consisting only of a single (dot), and sends a copy of the
       message found there to all of the addresses listed.  It determines  the
       network(s) to use based on the syntax and contents of the addresses.

       Local  addresses	 are  looked  up  in a file and aliased appropriately.
       Aliasing can be prevented by preceding the  address  with  a  backslash
       (\).  Normally  the sender is not included in any alias expansions; for
       example, if john sends to group, and group includes john in the	expan‐
       sion, then the letter will not be delivered to john.

       For additional information on mail, see the sendmail book by O'Reilly &
       Associates and the Sendmail Installation and  Operation	Guide  on  the
       Documentation CD-ROM.

   Sendmail Processing Options
       There  are a number of optional sendmail processing options that can be
       set.  Normally, these will be used  only	 by  a	system	administrator.
       They  can  be  set either on the command line using the -o option or in
       the configuration file.	(Refer to the  reference  page
       for details on the file.)


       The  following partial list is limited to those options that are likely
       to be useful on the command line.  For  a  complete  listing,  see  the
       Sendmail Installation and Operation Guide.

       Full  pathname  to  the	alias file.  The minimum number of free blocks
       (bminblocks) needed on the spool filesystem.  Sets the blank  substitu‐
       tion  character	to  the character specified in the Character argument.
       The sendmail daemon replaces unquoted spaces in addresses with  Charac‐
       ter.   The supplied configuration file uses a period (.) for Character.
       Causes sendmail to queue messages for that mailer daemon without	 send‐
       ing  them  if  an  outgoing  mailer is marked as expensive to use.  The
       queue can be run when costs are lower or when the queue is large enough
       to send the message efficiently.	 Sets the delivery mode to x. Delivery
       modes are i for interactive (synchronous) delivery,  b  for  background
       (asynchronous) delivery, and q for queue only (that is, actual delivery
       is done the next time  the  queue  is  run).   Tries  to	 automatically
       rebuild the alias database if necessary.	 Sets error processing to mode
       x.  Valid modes are the following:  Mails  the  error  message  to  the
       user's  mailbox,	 but  always exits with a 0 (zero) exit status (normal
       return).	 Mails the error message to the user's mailbox.	 Displays  the
       error message on the terminal (default).	 Throws away the error message
       and returns the exit status only.  Writes the error message to the ter‐
       minal or mails it if the user is not logged in.

	      If  the text of the message is not mailed by modes m or w and if
	      the sender is a local user, a copy of the message is appended to
	      the  dead.letter	file in the sender's home directory.  The mode
	      to use when creating temporary  files.   Saves  UNIX  compatible
	      style  From:  lines  at  the  front  of messages.	 Enables GECOS
	      fuzzy-logic name matching.

	      The GECOS field is a field in the /etc/passwd file that  usually
	      contains	the user's full name.  You can modify this information
	      by using the chfn routine.  If sendmail does not find  an	 exact
	      match  for  the user name, the Match-GECOS option tries to match
	      the user name against names in the /etc/passwd file.

	      For example, if user Jane Q. Public's user name is jpq, she will
	      receive  mail  sent  to  jane  if	 she  is  the only Jane in the
	      /etc/passwd file.	 Likewise, if John Doe's username  is  jd,  he
	      will  receive  mail  sent	 to  doe  if he is the only Doe in the
	      /etc/passwd file.

	      The sendmail Version 8 command and previous versions of sendmail
	      differ  in  how  they  process  GECOS information.  If the GECOS
	      option is enabled, sendmail Version  8  is  very	stringent;  it
	      requires	a match on the entire name. For instance, if the GECOS
	      field for user jd is "John Doe", then sendmail  Version  8  will
	      only  work for mail sent to john doe.  An older version of send‐
	      mail may work with john doe, john, or doe assuming that this  is
	      the  only john (or the only doe) in the file.  The default group
	      ID to use when calling mailers.  The SMTP help file.   Specifies
	      the maximum hop count.

	      The  maximum  hop	 count	option specifies the maximum number of
	      machines that a mail  message  can  be  sent  to	before	it  is
	      rejected.	  This	limit  is  used	 to help prevent infinite mail
	      loops.  The default is 30. Depending on the size	of  your  mail
	      system,  you  may	 require  a higher or lower minimum hop count.
	      Does not interpret a . (dot) on a line by itself	as  a  message
	      terminator.  Removes  the excess dot inserted by a remote mailer
	      at the beginning of a line if mail is received through SMTP.  In
	      addition,	 if  receiving mail through SMTP, any dot at the front
	      of a line followed by another dot is removed.  This is the oppo‐
	      site  of	the action performed by the X mailer option.  Indicate
	      that sendmail should use the Internet domain name server	if  it
	      can.   Send  error messages in Multipurpose Internet Mail Exten‐
	      sion (MIME) format.  Set connection cache time out.  Set connec‐
	      tion  cache  size.  Specifies the log level to be the value sup‐
	      plied in the number argument.  Each number includes the  activi‐
	      ties  of	all numbers of lesser value and adds the activity that
	      it represents. Valid levels and the activities that they	repre‐
	      sent  are	 as  follows:  Prevents	 logging.  Logs major problems
	      only.  Logs message collections  and  failed  deliveries.	  Logs
	      successful  deliveries.	Logs  messages	deferred (for example,
	      because the host is down).  Logs messages that are placed in the
	      queue  (normal  event).	Logs unusual but benign incidents (for
	      example, trying to process a locked file).   Logs	 the  internal
	      queue ID to external message ID mappings (the default). This can
	      be useful for tracing a message as it  travels  between  several
	      hosts.  Logs messages that are of interest when debugging.  Logs
	      verbose information regarding the queue.	If the sender uses  an
	      alias,  and  that	 sender	 is a member of the group named by the
	      alias, then also send to the sender.  Validates  the  right-hand
	      side  of	alias  rewrite rules when the sendmail daemon performs
	      the newaliases function.	If set,	 this  message	may  have  old
	      style  headers.	If not set, this message is guaranteed to have
	      new style headers (that is, commas  instead  of  spaces  between
	      addresses). If set, an adaptive algorithm is used that will cor‐
	      rectly determine the header format in  most  cases.   Identifies
	      the  person  who	is  to	receive	 a  copy of all returned mail.
	      Selects the directory in which to queue messages. The  directory
	      will  be	created	 if it does not exist.	The time-out on reads.
	      If none is set, sendmail will wait forever for  a	 mailer.  This
	      option  violates the word (if not the intent) of the SMTP speci‐
	      fication, so the time-out should probably be fairly large.

	      The sendmail Version 8 command has additional fine-grained  con‐
	      trol  of	timeouts.  See the Sendmail Installation and Operation
	      Guide on the Documentation CD-ROM	 for  additional  information.
	      Saves  statistics	 in  the  named file. Statistics are only col‐
	      lected if the file exists.  This file must  be  created  by  the
	      user.   The recommended path for this is /var/adm/sendmail/send‐	Statistics can be printed  out	using  /usr/sbin/mail‐
	      stats.   Always  instantiates the queue file, even under circum‐
	      stances where it is not strictly necessary. This provides safety
	      against  system  crashes	during delivery.  Sets the time-out on
	      undelivered messages in the queue to the specified  time.	 After
	      delivery	has failed (for example, because of a host being down)
	      for this amount of time, failed messages will be returned to the
	      sender.  The  default in the configuration file is 3 days.  Sets
	      the name of the time zone.  Sets the default user ID  for	 mail‐
	      ers.   Runs  in verbose mode.  The sendmail daemon delivers each
	      message in the mail queue from a separate process.  This	option
	      is  not  required; it can increase system overhead in this envi‐

   Aliases Interpretation
       In aliases, the first character of a name can  be  a  vertical  bar  to
       cause  interpretation  of the rest of the name as a command to pipe the
       mail to.	 It may be necessary to quote the name to keep	sendmail  from
       suppressing  the blanks from between arguments. For example, a file can
       contain a common alias such as:

       msgs: "|/usr/bin/msgs -s"

       Aliases can also have the syntax :include:filename to ask  sendmail  to
       read  the  named	 file  for a list of recipients. For example, an alias
       such as:

       poets: :include:/usr/local/lib/poets.list

       reads /usr/local/lib/poets.list for the list of addresses making up the

       You  can	 also  use the Network Information Service (NIS) to distribute
       your aliases to other systems.

   Exit Status
       The sendmail command returns an exit status describing what it did. The
       codes  are  defined  in	<sysexits.h>:  Successful  completion  on  all
       addresses.  The username was not recognized.  A catchall meaning neces‐
       sary  resources	were  not  available.	There is a syntax error in the
       address.	 There is an internal software error, including bad arguments.
       There  is a temporary operating system error, such as cannot fork.  The
       hostname was not recognized.  The message could	not  be	 sent  immedi‐
       ately, but was queued.

   Links to sendmail
       Three additional commands are links to sendmail: Prints the contents of
       the mail queue. This command is the same as running sendmail  with  the
       -bp  option.   Builds  a	 new  copy  of	the  alias  database  from the
       /var/adm/sendmail/aliases file. This command is	the  same  as  running
       sendmail	 with the -bi option.  Runs sendmail as a daemon. This command
       is equivalent to invoking sendmail with the -bd option.

   Mail Addresses
       Mail addresses are based on the	domain	address	 (Internet)  protocol.
       These addresses have the form: user@host.domain

       Note  that the configuration file provided with sendmail specifies that
       blanks in addresses be converted	 to  dots  before  being  transmitted.
       This convention follows the Internet mail protocol described in RFC822,
       but does not match the  Internet	 mail  protocol	 described  in	RFC733
       (NIC41952).   You  can  change this setting by setting the OB option in
       the sendmail  configuration  file  (see	the  reference
       page).	A  domain  is a logical grouping of systems that are connected
       together by physical network  links.   No  direct  relationship	exists
       between	the  actual physical interconnections and the way in which the
       systems are grouped in the domain.  The domain name identifies  a  spe‐
       cific  domain within a larger group of domains. The domain name has the
       format of a tree structure. Each node (or leaf) on the tree corresponds
       to  a  resource	set,  and each node can create and contain new domains
       below it. The actual domain name of a node is the path from the root of
       the tree to that node.

       For example, if node hera is part of the domain OSF, which is in turn a
       subdomain of ORG, a message sent to user geo at that address, uses this


       The  message  router  (usually sendmail) must determine how to send the
       message to its final destination.  If the router is at hera, it	deliv‐
       ers the message to user geo.  If the router is at another system within
       the OSF domain, it corresponds with the name server for that domain  to
       find out how to deliver the message. If the router is not a part of the
       OSF domain but is in a domain that is under the ORG domain,  it	corre‐
       sponds  with  the  name	server	for  the ORG domain to find out how to
       deliver the message. The	 respective  name  server  returns  a  network
       address	to the router. That network address determines the actual path
       that the message takes to its destination.

       The domain address is read from right to left, with each domain in  the
       address separated from the next domain by a (dot). This format does not
       imply any routing. Thus, although the example is specified  as  an  ORG
       address, the message might actually travel by a different route if that
       were more convenient or efficient.  At one site, the message associated
       with the sample address goes directly from the sender to node hera over
       a local area network.  At another site, it might be sent	 over  a  UUCP
       network or a combination of other delivery methods.

       Normally,  the  actual  routing	of a message is handled automatically.
       However, you can route the message manually through  several  specified
       hosts to get it to its final destination. An address using intermediate
       hosts,	called	 a   route   address,	has   the   following	 form:

       Explicitly  specifying  the message routing with these route addresses,
       while supported, is strongly discouraged by RFC	1123.  Instead,	 allow
       the mail software (for example sendmail) to handle routing issues.

       This address specifies that the message goes first to the remote system
       represented by hosta, then to the remote system represented  by	hostb,
       and  finally  to	 the  remote system represented by hostc. This path is
       forced even if there is a more efficient route to hostc.

       In some cases you may abbreviate the address rather than	 entering  the
       entire domain name.  In general, systems in the same domain do not need
       to use the full domain name. For example, a user on  node  zeus.XYZ.COM
       can  send  a  message  to  geo@hera.XYZ.COM  by	entering only geo@hera
       because they are in the same local domain, XYZ.COM.

       Other mail address formats exist and the mail  routing  program	(send‐
       mail) converts most of these other formats to a format that the network
       routing system can use.	However, if you use the domain address format,
       the routing program operates more efficiently.

       For example, if sendmail receives an address in the following format:


       it converts it to the corresponding domain address format:


       Similarly,  if  sendmail	 receives  an address in the following format:

       the mail routing program routes the message directly to the  uucp  com‐
       mand.   However,	 when  sending mail via uucp, you must include a route
       address that indicates which UUCP host(s) to send the  message  through
       to get to the final destination.

       To  route  messages  through the UUCP network, use one of the following
       domain address formats.	Your choice depends on the way	in  which  the
       systems	at  your  site	are  connected: @system_name.domain_name:uucp-

	      For example, the address: @zeus:hera!amy

	      sends a message to user amy on UUCP host hera by way  of	system
	      zeus.  The address: @apollo.802:merlin!lgh

	      sends  a	message	 to  user  lgh	on UUCP host merlin via system
	      apollo under the	local  domain  802.   uucp-route:!user-ID@sys‐

	      In this case, the address: merlin!arthur!amy@hera.802

	      sends  a message to user amy on system hera under domain 802 via
	      the    UUCP    link     merlin	 through     arthur.	  sys‐

	      In     this     example,	   the	  address:    @apollo.802:mer‐

	      sends a message to user amy on system hera under domain 802 that
	      first  goes through apollo, the gateway node for domain 802, and
	      then through the UUCP link merlin through arthur. (Including 802
	      in  this	example	 is  optional because the two domain names are
	      identical.)  hosta!hostb!hostc!user

	      This example is a purely	UUCP  route  address.	zeus!hera!kro‐

	      sends  a message to amy on kronos via the UUCP link zeus through
	      hera.  @hosta.UUCP:@hostb.UUCP:user@hostc

	      This example, like the previous one,  is	a  purely  UUCP	 route
	      address.	@zeus.UUCP:@hera.UUCP:amy@kronos.UUCP

	      sends  a message to amy on kronos via the UUCP link zeus through

	      Your host may also be configured	to  handle  DECnet  addresses.
	      Under DECnet Phase IV, an address is of the form nodename::user‐

	      This is typically converted into a domain-style  form,  such  as
	      user@nodename.dnet.parent-domain	 (parent-domain	 is  something
	      such as or OSF.ORG that uniquely identifies your com‐
	      pany).  Similarly,  your	host  may  also	 handle	 Phase	V type
	      addresses, such as

       By default, the Tru64 UNIX sendmail software uses message encoding that
       uses  8	bits of each byte. Although 8-bit encoding better supports the
       full range of characters in many non-English languages, 8-bit  encoding
       is not generally recommended because it violates the SMTP protocol used
       for mail transmission over a TCP/IP network.

       Specifies the command path.  The configuration file.  The raw data  for
       alias  names.   Sets  the option variable A to the full pathname of the
       aliases	file   (/var/adm/sendmail/aliases).    This   file   and   the
       aliases.dir  file  comprise the database of alias names.	 This file and
       the aliases.pag file comprise the database of alias names.   This  file
       specifies the users who should receive mail on the local host.

	      This option is not supported in Tru64 UNIX.  The help file.  The
	      collected statistics.  The mail queue directory.

       Except for /usr/sbin/sendmail and  /var/adm/,	 the  previous
       pathnames  are  all specified in the /var/adm/ file, so they
       may vary on your system.

       The process id of the daemon.

       Commands: mail(1), mailx(1), rc0(8)

       Functions: syslog(3)

       Files: aliases(4), forward(4),

       Specifications: RFC819, RFC821, RFC822

       Sendmail Installation and Operation Guide

       sendmail, Bryan Costales with Eric Allman, O'Reilly & Associates, Inc.


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