Subject: Linux Electronic Mail HOWTO
From: [email-masked] (Vince Skahan)
Date: Mon, 25 Apr 1994 19:47:54 GMT
Newsgroups: comp.os.linux.announce,comp.os.linux.admin,comp.answers,news.answers

Archive-name: linux/howto/mail
Last-modified: 19 Apr 94

  The Linux Electronic Mail HOWTO
  Vince Skahan, <[email-masked]>
  v1.5, Last modified 26 March 1994

  This  document describes the setup and care+feeding of Electronic Mail
  (e-mail) under Linux. You need to read this if you plan to communicate
  locally  or to remote sites via electronic mail. You probably do *not*
  need to read this document if  don't  exchange  electronic  mail  with
  other users on your system or with other sites.

  1.  Introduction

  The  intent  of  this  document is to answer some of the questions and
  comments that appear to  meet  the  definition  of  'frequently  asked
  questions' about e-mail software under Linux.

  This  document  and  the corresponding UUCP and News 'HOWTO' documents
  collectively supersede the UUCP-NEWS-MAIL-FAQ that has previously been
  posted to comp.os.linux.announce.

  1.1.  New versions of this document

  New   versions  of  this  document  will  be  periodically  posted  to
  comp.os.linux.announce, comp.answers,  and  news.answers.   They  will
  also  be  added  to  the  various anonymous ftp sites who archive such
  information including sunsite.unc.edu:/pub/Linux/docs/HOWTO.

  1.2.  Feedback

  I am interested in any feedback, positive or negative,  regarding  the
  content  of  this  document  via e-mail.  Definitely contact me if you
  find errors or obvious omissions.

  I read, but do not necessarily  respond  to,  all  e-mail  I  receive.
  Requests  for  enhancements will be considered and acted upon based on
  that day's combination of available time, merit of  the  request,  and
  daily blood pressure :-)

  Flames will quietly go to /dev/null so don't bother.

  Feedback concerning the actual format of the document should go to the
  HOWTO coordinator - Matt Welsh ([email-masked]).

  1.3.  Copyright Information

  The Mail-HOWTO is copyrighted (c)1994 Vince Skahan.

  A verbatim copy  may  be  reproduced  or  distributed  in  any  medium
  physical or electronic without permission of the author.  Translations
  are similarly permitted without express permission if  it  includes  a
  notice on who translated it.

  Short  quotes  may  be  used  without  prior  consent  by  the author.
  Derivative work and partial distributions of the  Mail-HOWTO  must  be
  accompanied  with  either a verbatim copy of this file or a pointer to
  the verbatim copy.

  Commercial redistribution is  allowed  and  encouraged;  however,  the
  author would like to be notified of any such distributions.

  In short, we wish to promote dissemination of this information through
  as many channels as possible. However, we do wish to retain  copyright
  on  the HOWTO documents, and would like to be notified of any plans to
  redistribute the HOWTOs.

  We further want  that  ALL  information  provided  in  the  HOWTOS  is
  disseminated.   If  you have questions, please contact Matt Welsh, the
  Linux HOWTO coordinator, at [email-masked], or +1 607 256 7372.

  1.4.  Standard Disclaimer

  Of course, I disavow any potential liability for the contents of  this
  document.  Use of the concepts, examples, and/or other content of this
  document is entirely at your own risk.

  1.5.  Other sources of information

  1.5.1.  LINUX HOWTO Documents:

  There is plenty of exceptional material provided in  the  other  Linux
  HOWTO  documents  and  from the Linux DOC project.  In particular, you
  might want to take a look at the following:

  o  the serial communications HOWTO

  o  the ethernet HOWTO

  o  the Linux Networking Guide

  1.5.2.  USENET:

             comp.mail.elm           the ELM mail system.
             comp.mail.mh            The Rand Message Handling system.
             comp.mail.mime          Multipurpose Internet Mail Extensions.
             comp.mail.misc          General discussions about computer mail.
             comp.mail.multi-media   Multimedia Mail.
             comp.mail.mush          The Mail User's Shell (MUSH).
             comp.mail.sendmail      the BSD sendmail agent.
             comp.mail.uucp          Mail in the uucp environment.

  1.5.3.  Mailing Lists:

  There is a smail-3.1 mailing list.  To join (or  get  off)  the  list,
  send mail to

          [email-masked]

  Make  sure  that  you include the address at which you want to receive
  mail in the text of the message.  To send a message to the list,  send
  it to

          [email-masked].

  1.5.4.  Books

  The following is a non-inclusive set of books that will help...

  o  "Managing  UUCP  and  USENET" from O'Reilly and Associates is in my
     opinion the best book out there for figuring out the  programs  and
     protocols involved in being a USENET site.

  o  "Unix   Communications"  from  The  Waite  Group  contains  a  nice
     description of all the pieces (and more) and how they fit together.

  o  "Sendmail"   from   O'Reilly  and  Associates  looks  to  like  the
     definitive reference on sendmail-v8 and sendmail+IDA.  It's a "must
     have"  for  anybody  hoping  to  make sense out of sendmail without
     bleeding in the process.

  o  "The Internet Complete Reference" from Osborne is a fine  reference
     book  that  explains the various services available on Internet and
     is a great "one-stop-shopping"  source  for  information  on  news,
     mail, and various other Internet resources.

  1.6.  Where *NOT* to look for help

  There  is  nothing  "special" about configuring and running mail under
  Linux (any more).  Accordingly, you almost certainly do *NOT* want  to
  be  posting  generic  mail-related  questions  to  the comp.os.linux.*
  newsgroups.

  Unless your posting is truly Linux-specific (ie, "please tell me  what
  routers are already compiled into the SLS1.03 version of smail3.1.28")
  you should be asking your  questions  in  one  of  the  newsgroups  or
  mailing lists referenced above.

  Let me repeat that.

  There  is  virtually  no  reason  to post anything mail-related in the
  comp.os.linux hierarchy any more.  There are  existing  newsgroups  in
  the comp.mail.* hierarchy to handle *ALL* your questions.

  IF  YOU  POST TO COMP.OS.LINUX.* FOR NON-LINUX-SPECIFIC QUESTIONS, YOU
  ARE LOOKING IN THE WRONG PLACE FOR HELP.  THE ELECTRONIC MAIL  EXPERTS
  HANG OUT IN THE PLACES INDICATED ABOVE AND GENERALLY DO NOT RUN LINUX.

  POSTING TO THE LINUX HIERARCHY FOR NON-LINUX-SPECIFIC QUESTIONS WASTES
  YOUR  TIME  AND  EVERYBODY  ELSE'S...AND IT FREQUENTLY DELAYS YOU FROM
  GETTING THE ANSWER TO YOUR QUESTION.

  2.  Hardware Requirements

  There are no specific hardware requirements for mail under Linux.

  You'll need some sort of 'transport' software  to  connect  to  remote
  systems, which means either tcp-ip or uucp.   This could mean that you
  need a modem or ethernet card (depending on your setup).

  3.  Getting the software

  In general, I grab my sources  from  ftp.uu.net  and  the  other  fine
  archive  sites  on Internet.  In addition, Linux-specific binary ports
  are found in the usual Linux  distrbutions  and  on  the  usual  Linux
  anonymous   ftp   sites   (sunsite.unc.edu   and   tsx-11.mit.edu   in
  particular).

  The newspak-2.1.tar.z distribution contains config  files  and  readme
  files  related  to  building uucp, news, and mail software under Linux
  from the various freely-available sources.  It can usually be found on
  sunsite.unc.edu in the directory /pub/Linux/system/Mail.

  4.  Mail 'Transport Agents'

  This section contains information related to 'transport agents', which
  means the underlying software  that  connects  your  local  system  to
  remote systems.

  4.1.  Smail v3.1

  Smail3.1 seems to be a de-facto standard transport agent for uucp-only
  sites and for some smtp sites.  It compiles without patching from  the
  sources.   In  addition,  smail  is provided in binary form in the SLS
  distribution of Linux.

  The newspak distribution contains config files for  smail3.1.28  under
  Linux that you can use to start with.

  If   you're   building   smail   from   sources,   you  need  to  have
  CASE_NO_NEWLINES=true in your os/linux file so that  'sed'  gives  you
  shell scripts that work properly.

  For  a  uucp-only  system  that  has  a  MX-record  and  that  wants a
  domainized header (who goes  through  a  smart-host  for  everything),
  these are the entire config files you'll need:

  o  replace 'subdomain.domain' with your domain name

  o  replace 'myhostname' with you un-domainized hostname

  o  replace 'my_uucp_neighbor' with the uucp name of your upstream site

             #-------- /usr/local/lib/smail/config -----------------
             #
             # domains we belong to
             visible_domain=subdomain.domain:uucp
             #
             # who we're known as (fully-qualified-site-name)
             visible_name=myhostname.subdomain.domain
             #
             # who we go through
             smart_path=my_uucp_neighbor
             #
             #---------- /usr/local/lib/smail/paths --------------
             #
             # we're a domainized site, make sure we accept mail to both names
             myhostname        %s
             myhostname.subdomain.domain      %s
             #
             #-------------------------------------------------------------------

  To run smail as a smtp daemon, add the following  to  /etc/inetd.conf:
  smtp stream tcp nowait  root  /usr/bin/smtpd smtpd

  Outgoing  mail  gets  sent  automatically,  when  using  elm.  If your
  internet link is down when you  send  mail,  then  the  mail  sits  in
  "/usr/spool/smail/input".   When the link next comes up, "runq" is run
  which causes the mail to be sent.

  4.2.  Sendmail+IDA

  I run  a  uucp-only  site  and  use  sendmail5.65b+IDA1.5  instead  of
  smail3.1.28  due  to  the  incredible  ease of use.  There is a binary
  distribution on sunsite.unc.edu in pub/Linux/system/Mail

  To install it...

  o  you'll probably want to remove (or rename) all the files from smail
     (see the /install/installed directory if you are SLS) to be safe.

  o  cd  to  /  then "gunzip -c sendmail5.65b+IDA1.5.tpz | tar xvf -" If
     you have a "modern" tar from a recent Slackware (for  example)  you
     can  probably  just  do a "tar -zxvf filename.tgz" and get the same
     results.

  o  cd to /usr/local/lib/mail/CF and copy the sample.m4  local.m4  file
     to  "yourhostname.m4".  Edit out the distributed hostname, aliases,
     and smarthost and put in  the  correct  one  for  your  site.   The
     default file is for a uucp-only site who has domainized headers and
     who talks to a smart host.  Then "make  yourhostname.cf"  and  move
     the resulting file to /etc/sendmail.cf

  o  if you are uucp-only, you do *NOT* need to create any of the tables
     mentioned in the README.linux file.  You'll just have to touch  the
     files  so  that  the  Makefile works.  Just edit the .m4 file, make
     sendmail.cf, and start testing it.

  o  if you're uucp-only and you talk  to  sites  in  addition  to  your
     "smart-host",  you'll  need  to add uucpxtable entries for each (or
     mail to them will also go through  the  smart  host)  and  run  dbm
     against the revised uucpxtable.

  o  if  you use my sendmail5.67b+IDA1.5 distribution you should not use
     a "freeze file".

  o  If you run Rich Braun's  original  binary  distribution  of  5.67a,
     you'll need to freeze the configuration if you change your .cf file
     with "/usr/lib/sendmail -bz" to make the changes take effect.   You
     should  also update your version to at least 5.67b since there is a
     nasty security hole in 5.67a and earlier.

  Another nice thing is that if you have  mail.debug  set  and  you  run
  syslogd,  your  incoming  and  outgoing mail messages will get logged.
  See the /etc/syslog.conf file for details.

  The sources for sendmail+IDA may be found at  uxc.cso.uiuc.edu.   They
  require no patching to run under Linux.

  If  you're  going  to run sendmail+IDA, I strongly recommend you go to
  the sendmail5.67b+IDA1.5 version  since  all  required  Linux-specific
  patches are now in the vanilla sources and several security holes have
  been plugged that WERE (!!!) in the older version you may have grabbed
  or built before about December 1st, 1993.

  4.3.  Sendmail 8.6

  Sendmail  8.6.x  from  Berkeley  is  the  latest  major revision after
  sendmail5.  It has  wonderful  built-in  support  for  building  under
  Linux.  Just "make linux" and you'll be all set.

  4.4.  Other "transport agents"

  The following also are known to run under Linux.  Consult "archie" for
  details regarding how to find them...

  o  smail2.5 - very simple UUCP-based smail

  4.5.  Local Delivery Agents

  Unlike most operating systems, Linux does not  have  mail  "built-in".
  You'll need a program to deliver the local mail.

  One good program is Rich Braun's "lmail" program, but I've switched to
  using the more commonly available "deliver" program.

  Documentation for how to use either  for  local  delivery  is  in  the
  sendmail5.67b+IDA1.5 binary release (on sunsite) mentioned above.

  5.  Mail "User Agents"

  This  section  contains  information  related  to "user agents", which
  means the software the user sees and uses.  This  software  relies  on
  the "transport agents" mentioned above.

  5.1.  Elm

  Elm  compiles,  installs,  and  runs flawlessly under Linux.  For more
  information, see the elm sources and installation instructions.

  The only thing to know is that Elm's Configure script incorrectly sets
  the  "ranlib"  variable  in  config.sh.   When Configure gives you the
  chance to edit config.sh before  proceeding,  please  do  so  and  set
  "ranlib='ranlib'"  or the binaries will compile but not link.  The Elm
  Development Team has been informed of this little problem,  so  please
  don't bother them with it (again).

  Elm  and filter need to be mode 2755 (group mail) with /usr/spool/mail
  mode 775 and group mail.

  If  you  use  a  binary  distribution,  you'll  need   to   create   a
  /usr/local/lib/elm/elm.rc  file  to  override the compiled-in hostname
  and domain information:

  o  replace "subdomain.domain" with your domain name replace

  o  "myhostname" with you un-domainized hostname replace

  o  "my_uucp_neighbor" with the uucp name of your upstream site

             #---------- /usr/local/lib/elm/elm.rc ------------------
             #
             # this is the unqualified hostname
             hostname = myhostname
             #
             # this is the local domain
             hostdomain = subdomain.domain
             #
             # this is the fully qualified hostname
             hostfullname = myhostname.subdomain.domain
             #
             #--------------------------------------------------------

  One thing you want to be aware of is that if you have Elm compiled  to
  be MIME-able, you need metamail installed and in your path or Elm will
  not be able to read MIME mail you've received.  Metamail is  available
  on thumper.bellcore.com and of course via "archie".

  5.2.  Mailx

  There  is a fine binary implementation of mailx located on the various
  Linux archive sites.  Make sure you grab version 5.3b or  later  since
  there are security problems in v5.3a.

  The  only  potential  problem  I'm  aware  of  is  that it seems to be
  compiled  in  a  way  that   requires   /usr/lib/smail   rather   than
  /usr/lib/sendmail  as  a transport agent.  You probably need a link if
  you run sendmail on your system.

  I strongly recommend removing the old "edmail" stuff from SLS1.00  and
  replacing it with mailx.

  5.3.  Other user agents

  The following also are known to run under Linux.  Consult "archie" for
  details regarding how to find them...

  o  Pine      - from the Univ. of Washington

  o  Metamail  - allows MIME support

  o  mh        - yet another way to handle mail

  o  deliver   - file/process mail based on rules

  o  procmail  - file/process mail based on rules

  o  Majordomo - manages e-mail lists

  o  Mserv     - provide files-by-mail

  6.  Acknowledgements

  The following people have helped in the assembly  of  the  information
  (and experience) that helped make this document possible:

  Steve Robbins, Ian Kluft, Rich Braun, Ian Jackson, Syd Weinstein, Ralf
  Sauther, Martin White, Matt Welsh, Ralph Sims, Phil Hughes

  If I forgot anybody, my apologies...