SMTP(8zm)                                                            SMTP(8zm)

       smtp - zmailer SMTP client transport agent

       smtp [-1678deEHMrPsVxXW]  [-A /path/to/smtp-auth-secrets.txt] [-c chan-
            nel]  [-h heloname]  [-l logfile]  [-O options]   [-p remote-port]
            [-T timeouts]     [-w sockwbufsize]    [-S /path/to/smtp-tls.conf]
            [-F forcedest] [-L localidentity] host

       The smtp(8zm) is a ZMailer transport agent which is usually only run by
       the scheduler(8zm) to transfer messages to a remote Internet host using
       the SMTP protocol.  The smtp(8zm) program must be  run  with  the  same
       current directory as the scheduler(8zm), namely POSTOFFICE/transport.

       The  program  scans  the  message  control  files  named  on  stdin for
       addresses destined for its channel and the host given  on  the  command
       line.  If any are found, all matching addresses and messages are trans-
       ferred in a single SMTP conversation.  The destination  host  might  in
       fact be served by any available mail exchanger for that host.

       -1     Worsen  system performance, send only one message per connection
              to given target system.  (That is,  reopen  the  connection  for
              each messge.)

       -6     Prefer IPv6 type socket and addresses, if available.

       -7     forces  SMTP  channel  to  be  7-bit, and thus forcing all 8-bit
              texts to be MIME-QP-encoded for the transport.

              This does same as -7 but also blocks  of  all  ESMTP  extensions
              from use.

              This  ``double-7''  option  can  be followed by ``-8'' option to
              force the channel to be 8-bit transparent, and  even  to  decode
              MIME-QP TEXT/PLAIN, but to do it without any ESMTP.

       -8     forces  SMTP  channel  to be 8-bit-clean, and as such, to decode
              the message while transporting it (is it is MIME QP encoded).

       -A /path/to/smtp-auth-secrets.txt
              Defined file with application  specific  authentication  secrets
              for use against some LMTP target systems.

       -c channel
              specifies which channel name should be keyed on.  The default is

       -d     turns on debugging output.

       -e     asks that for every destination  address  specification  with  a
              matching  channel  name, an MX lookup is done on the hostname to
              see whether the currently connected host can provide service for
              that destination.  The default is to just do a textual name com-
              parison with the destination hostname as given  on  the  command

       -E     use the "EHLO"-greeting only if the remote server initial banner
              reports "ESMTP" on it.

       -h host
              specifies the hostname for the SMTP HELO greeting.  The  default
              is  the  hostname  of  the local system, as returned by gethost-
              name(2) or uname(2).

       -F forcedest
              overrides delivery destination by forceing all email to be  sent
              to given forcedest.

              Understood formats for the forcedest are:

                             Connects  to  named  UNIX-domain  socket in local

                             Literal IPv6 address for IPv6 system

                             Literal IPv4 address for non-IPv6 system

                             DNS/hosts data registered name

       -H     Disable the per default active forced 8-bit  headers  conversion
              into MIME-2-format.

       -L localident
              specifies (for multi-homed machines) that they should use speci-
              fied identity when connecting  to  the  destination.   Think  of
              server  with  multiple  IP  numbers  due to virtual hosting, for
              example.  At such systems there may be  situation  when  virtual
              identity needs to be used for reaching the destination system.

              Understood formats for local identity are:

                             (eth0 device in the system)

                             Literal IPv6 address for IPv6 system

                             Literal IPv4 address for non-IPv6 system

                             DNS/hosts data registered name

       -l logfile
              specifies a log file where the complete SMTP command transaction
              will be copied.  Each line in the log will be prefixed with  the
              process  id of the transport agent process, so the same log file
              can be used by all SMTP clients.

              specifies that system shall run in RFC 2033 specified LMTP  mode
              when contacting remote systems.

              Usage  of  this  option  requires  also that destination port is
              defined, and is not the SMTP default of  25.   Preferrably  even
              running in "punt" mode (-F option).

              Alternate is to use "punt" mode (-F option) to a UNIX-socket.

       -r     Asks  to  set up SMTP connections using a source TCP port number
              under 1024.  This is in the range of port numbers only available
              to  a  privileged process on some UNIX systems, which has led to
              some misguided attempts at mail security based  on  this  mecha-

       -s     asks  to  report  the progress of the SMTP conversation and data
              transfer on the command line in a way that will  be  visible  to

       -x     Turns  off MX lookups on delivery connections.  This may be used
              ignore public MX knowledge and do exactly what the  router  says
              in  cases where delivering to an explicit IP address is inappro-

       -X     Allow connection to local address.  This may be used in conjunc-
              tion  with  -x  option  only,  if  no  -x  option present, -X is
              silently ignored.

              Generic text-keyword option interface.

                     Even when distributing lists in  EZMLM-mode,  ignore  any
                     such.   Useful  in cases where EZMLM-mode results message
                     count multiplication to leading to delivery slowdown...

       -P     disable SMTP-PIPELINING usage (ESMTP keyword: PIPELINING)

       -S /path/to/smtp-tls.conf
              Transport-Layer-Security  (a.k.a.  Secure-Socket-Layer)  feature
              configuration  file.   When this is supplied, and system is com-
              piled to possibly use it, and the  remote  system  reports  EHLO
              capability  of  STARTTLS,  this  client  attempts to turn on the
              encryption on the socket.  There exists also a  posssibility  of
              demanding  TLS  mode  of the connection - if so has been demand,
              but it is not available, email is not sent over the  connection.

       -T timeouts
              specifies  the timeouts when waiting for various things.  Possi-
              ble submodes are:

                     Timeout to wait for  the  TCP  connection  establishment.
                     The default is 3 minutes.

                     Timeout  to  wait at lowlevel TCP socket write() routines
                     for the socket to accept some more input.  The default is
                     5 minutes.

              cmd=5m (or plain value)
                     Waiting for command replies (e.g. MAIL FROM,  The
                     default is 5 minutes.

                     From "DATA" verb  issuance  until  "354"  responce.   The
                     default is 2 minutes.

                     From  "DATA"  phase  ending  "."  issuance until "250 OK"
                     report reception (this is after the  TCP  write  pipeline
                     has  completed).   The  default  is 20 minutes. (RFC 1123
                     gives 10 minutes.)

       -V     prints a version message and exits.

       -w sockwbufsize
              Sets the local socket write buffer size  to  non-default  value.
              Some  Win-NT  systems seem to want to have unbelievably low val-
              ues, like 2000 bytes which appears as acceptance  of  two  first
              TCP  frames,  and discard of all the rest which high-performance
              systems usually send.  Some Solaris versions then  go  to  "lost
              packet retry backoff" from which they never really recover.

       -W     turns on the DNS WKS checking, and if the remote system does not
              have SMTP in its WKS-bits, email delivery  to  such  address  is
              aborted with an error message.

       This  program  reads  in processable file names relative to the current
       working directory of the scheduler  (namely:  $POSTIOFFICE/transport/).
       Optionally  on the same line the scheduler may tell which host is to be
       looked for from the recipients of the message.

              relative-spool-path [ <TAB> hostname ]

       This program produces diagnostic output on the standard output.  Normal
       diagnostic output is of the form:

              id/offset<TAB>notify-data<TAB>status message

       where id is the inode number of the message file, offset is a byte off-
       set within its control file where the  address  being  reported  on  is
       kept,  status  is  one  of  ok,  error, or deferred, and the message is
       descriptive text associated with the report.  The text is terminated by
       a linefeed.  Any other format (as might be produced by subprocesses) is
       passed to standard output for logging in the scheduler log.

       The exit status is a code from <sysexits.h>.

       When user sends out 8-bit mail with proper  headers,  this  module  can
       send  it  out to conforming servers either in 8-bit transparent manner,
       or down-converting Content-Transfer-Encoding: 8BIT to Content-Transfer-
       Encoding: 7BIT or Content-Transfer-Encoding: QUOTED-PRINTABLE depending
       on what is the mail contents.

              This works only with Content-Type: text/plain thus no fancy mul-
              tipart/alternate schemes..

       When  ``Content-Transfer-Encoding:''-header is not present in the head-
       ers, and recipient has not declared 8-bit SMTP  capability,  mail  con-
       tents are treated with old 7-bit stripping method.

       If you are using a version which has been made to use OpenSSL 0.9.4, or
       later version, you are able to encrypt the  SMTP  protocol  session  in
       case the remote end supports RFC 2487 defined STARTTLS facility.

       Possible example of the smtp-tls.conf  file is given below:

       #| This is example configuration file for TLS support at the SMTP TA
       #| programs, e.g. SMTP Client.

       tls-cert-file   /opt/mail/db/smtpserver-cert.pem
       tls-key-file    /opt/mail/db/smtpserver-key.pem
       tls-CAfile      /opt/mail/db/smtpserver-CAcert.pem
       #tls-CApath /path/to/CAdir/
       #tls-loglevel  0  # Value from 0 thru 4

       #tls-random-source  dev:/dev/urandom
       #tls-random-source  egd:/var/run/egd-pool

       #| If the TLS mode is MANDATED for a session, copy this file to
       #| e.g. "smtp-tls-mandatory.conf", uncomment following line, and
       #| point those channels to use that new file.

       The  code  is  doing this in application specific, and in a very sloppy
       manner!  Following interaction is presumed to happen and be  valid  for
       this use:

        C: AUTH LOGIN
        S: 334 VXNlcm5hbWU6                  base64 "Username:"
        C: bXluYW1l                          base64 "myname"
        S: 334 Uc2VjcmV0                     base64 "Password:"
        C: GFzc3dvcmQ6                       base64 "secret"
        S: 235 Authentication successful

       Where  'myname'  and  'secret' are those of CYRUS IMAP server system...
       (or whatever is applicable to your case)  Possibly  this  shall  happen
       under TLS encryption.

       The  SMTP-AUTH-SECRETS.TXT  file  has authentication secrets for remote
       hosts, keep the file well protected!

       Any empty line, or mere whitespace line, is ignored.  Lines with  first
       non-whitespace char being '#' are comments.

       Other lines are presumed to be whitespace separated quads:
            channel   remotehost   remoteuser   remotesecret

         The 'channel' can be either "*" matching any runtime channel parame-
          ter, or literal something, like: "smtp-lmtp".   (Without  quotes  in
          the file, though.)  Matching is done case sensitive.

         The  'remotehost'  is  remote  host name on which the connection has
          gone to (e.g. by MXes, or whatever means).  Matching  is  done  case

         The  'remoteuser'  is BASE64 encoded string to be sent to the remote
          system in SMTP-auth transaction.

         The 'remotesecret' is BASE64 encoded string to be sent to the remote
          system in SMTP-auth transaction.

              This  environment  variable is expected to be inherited from the
              scheduler(8zm), and it tells where  scheduler's  idea  of  ZENV-
              variables are located at.

       TBW: many variables!

       /opt/mail/zmailer.conf   (ZCONFIG)
       /var/spool/postoffice    (POSTOFFICE)

       router(8zm), scheduler(8zm), zmailer.conf(5zm).

       RFC 821                The basic SMTP specification
       RFC 822                Mail header format
       RFC 974                MX routing
       RFC 1123               Various 821 parameter clarifications

       Several extended SMTP facilities are implemented:

       RFC 1341/1521/2045     MIME specification (body, formats)
       RFC 1342/1522/2047     MIME specification (headers)
       RFC 1425/1651/1869     ESMTP EHLO framework
       RFC 1426/1652          ESMTP 8BITMIME
       RFC 1427/1653/1870     ESMTP SIZE
       RFC 1428               Basic MIME conversion rules
       RFC 1830/3030          ESMTP CHUNKING
       RFC 1854/2197/2920     ESMTP PIPELINING
       RFC 1891/3461          ESMTP DSN
       RFC 1893/2034          ESMTP ENHANCEDSTATUSCODES
       RFC 1893/3463          Enhanced Mail System Status Codes
       RFC 1985               ESMTP ETRN
       RFC 2033               LMTP client mode
       RFC 2487               ESMTP STARTTLS
       RFC 2554+M$ Exchange   ESMTP AUTH LOGIN
       RFC 2554+NetScape      ESMTP AUTH=LOGIN
       RFC 2852               ESMTP DELIVERBY

       This program authored and copyright by:
          Rayan Zachariassen <no address>
       Heaps of extended SMTP facilities by:
          Matti Aarnio <>

                                  2005-Mar-24                        SMTP(8zm)