The Linux Electronic Mail HOWTO

Vince Skahan, <vince@halcyon.com> v1.17, 22 Oct 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.

Contents

1 Introduction 2 1.1 New versions of this document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Copyright Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.4 Standard Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.5 Other sources of information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.5.1 LINUX HOWTO Documents: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.5.2 USENET: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.5.3 Books . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.6 Where *NOT* to look for help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Hardware Requirements 4

3 Getting the software 5

4 Mail ’Transport Agents’ 5 4.1 Smail v3.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Sendmail+IDA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.2.1 The sendmail.m4 file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.2.2 Defining a local mailer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.2.3 The Sendmail+IDA dbm Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.2.4 So Which Entries are Really Required? . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.3 Sendmail 8.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.4 Other ”transport agents” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.5 Local Delivery Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 5 Mail ”User Agents” 11

5.1 Elm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.2 Mailx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5.3 Other user agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6 Acknowledgements 13

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.

In addition, you should be generally able to find this document on the Linux World-

WideWeb home page at http://sunsite.unc.edu/mdw/linux.html and on my home page at
http://www.halcyon.com/vince/welcome.html.

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

(mdw@sunsite.unc.edu).

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 mdw@sunsite.unc.edu.

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:

• the Serial Communications HOWTO

• the Ethernet HOWTO

• the Linux Networking Administrators’ 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.smail         the smail mail agent.
           comp.mail.uucp          Mail in the uucp environment.

1.5.3 Books

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

• ”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.

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

• ”Sendmail” from O’Reilly and Associates looks to be 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.

• ”The Internet Complete Reference” from Osborne is a fine reference book that explains the various services available on Internet and is a great source for information on news, mail, and various other Internet resources.

   • ”The Linux Networking Administrators' Guide” from Olaf Kirch of the Linux DOC Project is

available on the net and is also published by (at least) O’Reilly and SSC. It makes a fine one-stop shopping to learn about everything you ever imagined you’d need to know about Unix networking.

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 LOOK-ING 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-2.4.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 in

sunsite.unc.edu:/pub/Linux/system/Mail/news. If you can’t find it on sunsite, please send me mail

and I’ll make sure you get a copy of it.

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 the following in your os/linux file so that ’sed’ gives you shell scripts that work properly.

        CASE_NO_NEWLINES=true

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:

• replace ’subdomain.domain’ with your domain name

• replace ’myhostname’ with you un-domainized hostname

• 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 sendmail5.67b+IDA1.5 instead of smail3.1.28 due to the incredible ease of

use. There is a binary distribution in sunsite.unc.edu:pub/Linux/system/Mail/delivery. To install it:

• 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.

• cd to / then ”gunzip -c sendmail5.67b+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.

• 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

• 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.

• 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.

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

• 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 vixen.cso.uiuc.edu. They require no patching to run under Linux if you’re running something like a kernel of 1.00.

If you’re running a current kernel of around 1.1.50, you get the fun of reversing most of the Linux-specific patches that are now in the vanilla sources. It’s extremely obvious where this needs to be done. Just type make and when it blows up, go to that line in the sources and comment out the Linux-specific code that’s in there.

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.

The May/June 1994 edition of Linux Journal has an extensive article on the care and feeding of sendmail+IDA. The new edition of the Linux DOC Project Networking Administrator's Guide will have an even more detailed and complete version.

4.2.1 The sendmail.m4 file

Sendmail+IDA requires you to set up a sendmail.m4 file rather than editing the sendmail.cffile directly. The nice thing about this is that it is simple to set up mail configurations that are extremely difficult (if not totally impossible for most people to set up correctly) in smail or traditional sendmail.

The sendmail.m4 file that corresponds to the above smail example looks like the following:

  dnl #------------------ SAMPLE SENDMAIL.M4 FILE ------------------
  dnl #
  dnl # (the string 'dnl' is the m4 equivalent of commenting out a line)
  dnl #
  dnl # you generally don't want to override LIBDIR from the compiled in paths
  dnl #define(LIBDIR,/usr/local/lib/mail)dnl    # where all support files go
  define(LOCAL_MAILER_DEF, mailers.linux)dnl    # mailer for local delivery
  define(POSTMASTERBOUNCE)dnl                   # postmaster gets bounces
  define(PSEUDODOMAINS, BITNET UUCP)dnl         # don't try DNS on these
  dnl #

dnl #-------------------------------------------------------------
dnl #
dnl # names we're known by
define(PSEUDONYMS, myhostname.subdomain.domain myhostname.UUCP)
dnl #
dnl # our primary name
define(HOSTNAME, myhostname.subdomain.domain)
dnl #
dnl # our uucp name
define(UUCPNAME, myhostname)dnl
dnl #
dnl #-------------------------------------------------------------
dnl #
define(UUCPNODES, |uuname|sort|uniq)dnl       # our uucp neighbors
define(BANGIMPLIESUUCP)dnl                    # make certain that uucp
define(BANGONLYUUCP)dnl                       #  mail is treated correctly
define(RELAY_HOST, my_uucp_neighbor)dnl       # our smart relay host
define(RELAY_MAILER, UUCP-A)dnl               # we reach moria via uucp
dnl #
dnl #--------------------------------------------------------------------
dnl #
dnl # the various dbm lookup tables
dnl #
define(ALIASES, LIBDIR/aliases)dnl            # system aliases
define(DOMAINTABLE, LIBDIR/domaintable)dnl    # domainize hosts
define(PATHTABLE, LIBDIR/pathtable)dnl        # paths database
define(GENERICFROM, LIBDIR/generics)dnl       # generic from addresses
define(MAILERTABLE, LIBDIR/mailertable)dnl    # mailers per host or domain
define(UUCPXTABLE, LIBDIR/uucpxtable)dnl      # paths to hosts we feed
define(UUCPRELAYS, LIBDIR/uucprelays)dnl      # short-circuit paths
dnl #
dnl #--------------------------------------------------------------------
dnl #
dnl # include the 'real' code that makes it all work
dnl # (provided with the source code)
dnl #
include(Sendmail.mc)dnl                         # REQUIRED ENTRY !!!
dnl #
dnl #------------ END OF SAMPLE SENDMAIL.M4 FILE -------

4.2.2 Defining a local mailer

Unlike most Unix distributions, Linux does not come with a local mail delivery agent by default. I recommend using the commonly available deliver program, which is an optional package in a number of the usual Linux distributions. In order to do so, you need to define a LOCAL MAILER DEF in the sendmail.m4 file that points to a file that looks like:

  # -- /usr/local/lib/mail/mailers.linux --
  #     (local mailers for use on Linux )
  Mlocal, P=/usr/bin/deliver, F=SlsmFDMP, S=10, R=25/10, A=deliver $u
  Mprog,  P=/bin/sh,       F=lsDFMeuP,   S=10, R=10, A=sh -c $u

There is a also built-in default for deliver in the Sendmail.mc file that gets included into the sendmail.cf file. To specify it, you would not use the mailers.linux file but would instead define the following in your sendmail.m4 file:

   dnl --- (in sendmail.m4) ---
   define(LOCAL_MAILER_DEF, DELIVER)dnl       # mailer for local delivery

Unfortunately, Sendmail.mc assumes deliver is installed in /bin, which is not the case with Slackware1.1.1 (which installs it in /usr/bin). In that case you’d need to either fake it with a link or rebuild deliver from sources so that it resides in /bin.

4.2.3 The Sendmail+IDA dbm Tables

Setting up special behavior for sites or domains is done through a number of optional dbm tables rather than editing the sendmail.cf file directly. Refer to the July-1994 issue of Linux Journal, to the docs in the sources, or to the sendmail chapter in the newest version of the Linux DOC Project Networking Administration Guide which will be available real-soon-now for more details.

• mailertable - defines special behavior for remote hosts or domains.

• uucpxtable - forces UUCP delivery of mail to hosts that are in DNS format.

• pathtable - defines UUCP bang-paths to remote hosts or domains.

• uucprelays - short-circuits the pathalias path to well-known remote hosts.

• genericfrom - converts internal addresses into generic ones visible to the outside world.

• xaliases - converts generic addresses to/from valid internal ones.

• decnetxtable - converts RFC-822 addresses to DECnet-style addresses.

4.2.4 So Which Entries are Really Required?

When not using any of the optional dbm tables, sendmail+IDA delivers mail via the DEFAULT MAILER (and possibly RELAY HOST and RELAY MAILER) defined in the sendmail.m4 file used to generate sendmail.cf. It is easily possible to override this behavior through entries in the domaintable or uucpxtable.

A generic site that is on Internet and speaks Domain Name Service, or one that is UUCP-only and forwards all mail via UUCP through a smart RELAY HOST, probably does not need any specific table entries at all.

Virtually all systems should set the DEFAULT HOST and PSEUDONYMS macros, which define the canonical site name and aliases it is known by, and DEFAULT MAILER. If all you have is a relay host and relay mailer, you don’t need to set these defaults since it works automagically.

UUCP hosts will probably also need to set UUCPNAME to their official UUCP name. They will also probably set RELAY MAILER, and RELAY HOST which enable smart-host routing through a mail relay. The mail transport to be used is defined in RELAY MAILER and should usually be UUCP-A for UUCP sites.

If your site is SMTP-only and talks ‘Domain Name Service’, you would change the DEFAULT MAILER to TCP-A and probably delete the RELAY MAILER and RELAY HOST lines.

If you’re a SLIP site, you might want to take the easy way out and just forward all outgoing mail to your service provider to do the right thing with. To do so, you’d want to define ISOLATED DOMAINS and VALIDATION DOMAINS to be your domain, you’d also want to define RELAY HOST to be your service provider and RELAY MAILER to be TCP. Of course, you want to ask permission before you set any system up as your general purpose relay.

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...

• 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 up to and through Slackware 1.1.1 (gcc2.4.5, gcclib 4.4.4). 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. The Elm Development Team has been informed of this little problem, so please don’t bother them with it (again).

• (from Chip Rosenthal - chip@chinacat.unicom.com ) The easiest way to deal with this is to create a file called config.over at the top of you Elm source tree and include the line:

     ranlib='ranlib'

• Alternatively, you can just remember to correctly edit the line in config.sh when Configure gives you the chance to do so.

• 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 compiledin hostname and domain information:

• replace ”subdomain.domain” with your domain name replace

• ”myhostname” with you un-domainized hostname replace

• ”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”.

We have heard reports that gcc and gcclib newer than v2.4.5 and v4.4.4 respectively are rather strict and fail to compile Elm. Here’s the scoop as reported by ccnp@unitrix.utr.ac.za (Neil Parker) who forwarded a posting by longyear@netcom.com (Al Longyear).

• ELM is using internal fields in the FILE structure in an effort to bypass the standards. (The flag, IOERR, and IOEOF are old fields for the pre-POSIX runtime package. While POSIX doesn’t say that you can’t define these fields, it does not say that you must . Linux does not. It does say that programs should not be written to use them, even if they are in the implementation.)

              where it does         if (fp->_flag & _IOERR) ...
              change it to          if (ferror(fp)) ....
              where it does         if (fp->_flag & _IOEOF) ...
              change it to          if (feof(fp)) ...
              These are the ANSI/POSIX definitions for the same function.

• While this item is not Linux-specific, it’s a nagging bug nevertheless. We’ve heard that Elm sometimes fails with a message that it’s unable to malloc() some massive number of bytes. This has been identified as an Elm Bug. The identified workaround is to remove the post-processed global mail aliases (aliases.dir and aliases.pag).

• (from scot@catzen.gun.de (Scot W. Stevenson) )

The current metamail package requires csh for some of its scripts. Failure to have csh (or tcsh) will cause most interesting errors...

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. If you’re into building from sources, mailx v5.5 compiles without patching under Linux if you have "pmake" installed.

The only potential problem I’m aware of with the binary distribution on sunsite 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.

If anybody is still using it, 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...

• Pine - from the Univ. of Washington

• Metamail - allows MIME support

• mh - yet another way to handle mail

• deliver - file/process mail based on rules

• procmail - file/process mail based on rules

• Majordomo - manages e-mail lists

• 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, Chip Rosenthal, Scot Stevenson, Neil Parker If I forgot anybody, my apologies...