Aminet 4/Aminet 4 - November 1994.iso/aminet/comm/mail/amigaelm_v4.lha/other/MIME.faq

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From: [e-mail] (Tim Goodwin)
Newsgroups: comp.mail.mime,comp.answers,news.answers
Subject: comp.mail.mime frequently asked questions list (FAQ)
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Summary: This posting contains answers to some of the Frequently Asked
    Questions about MIME (Multipurpose Internet Mail Extensions).
    Please read it before posting a question to comp.mail.mime.
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comp.mail.mime frequently asked questions list (FAQ)


0.1 Introduction

This is a Frequently Asked Questions document about MIME, the
multipurpose and multi-media standard for Internet mail.

It was begun by, and is largely the work of, Ed Vielmetti.  It is now
maintained by me, Tim Goodwin.


0.2 Conventions

I have used some typographical conventions.  Eventually I hope to
format this as simplemail, but in the meantime...

Direct quotations begin with an attribution in a standard format, and
are indented by four spaces.

FTPable goodies appear in a standard (obvious, I hope) format,
indented by eight spaces.  Note that I usually list only the
distribution site -- please try your nearest FTP archive first.

Meta-text appears as comments in the style of C code, like this.

/* There weren't any bracketing characters left, otherwise I would
   have used them.
 */

Generally, these indicate places where information is missing, I'm
unsure of my ground, or I plan major changes in the near future.

You can ignore these if you're just looking for information.  But if
you can help fill in the gaps, and you want to achieve fame, fortune,
and your name at the bottom of this FAQ, please mail me.


1 INDEX TO THE FAQ

2 What is MIME?
2.1 Introduction
2.2 MIME features that may or may not be present
2.3 Further information
2.4 MIME glossary
2.5 MIME-relevant RFCs and other standards
2.6 List of registered MIME types
2.7 Internet Engineering Task Force (IETF) working groups
2.8 Newsgroups and mailing lists

3 Freely available MIME software packages
3.1 metamail
3.2 MIXMH
3.3 MH 6.8 and 'mhn'
3.4 Pine
3.5 c-client
3.6 Andrew
3.7 elm
3.8 MIME tools for NeXT
3.9 Conversions from other mail systems
3.9.1 uuencode to MIME
3.9.2 Sun OpenWindows mail to MIME
3.9.3 NeXTmail to MIME
3.10 MIME for VMS MAIL (HUyMailer)

4 Commercial MIME software packages
4.1 IBM multimedia mail for OS/2
4.2 Innosoft PMDF for VMS
4.3 Control Data Systems Mail*Hub package
4.4 cc:MAIL support for MIME
4.5 Z-code Z-Mail
4.6 STI Document Browser
4.7 Frontier Technologies Super-TCP mail system
4.8 PP
4.9 HP's MPOWER

5 Miscellaneous questions
5.1 What can I use to display MIME messages?
5.2 What's "text/enriched"?  "text/simplemail"?
5.3 What about security issues?
5.4 So, does MIME introduce any new security problems?
5.5 What about a group 3 facsimile encoding?
5.6 Should I always use external body parts to save space?
5.7 What mail servers can I reference?
5.8 How can I register a new MIME type?
5.9 What's ESMTP, and how does it affect MIME?

6 MIME information available from the Internet
6.1 Anonymous FTP
6.2 Mail based archive servers
6.2.1 Eitech "ServiceMail"
6.2.2 Metamail "mailserver"
6.3 Gopher

7 Published books and articles

8 MIME based relays for commercial mail services
8.1 Large national or international providers
8.1.1 ATTMAIL
8.1.2 Radiomail
8.2 Local and regional providers

9 MIME and Usenet news
9.1 Introduction
9.2 nn

10 Acknowledgements


2 What is MIME?

2.1 Introduction

MIME, the Multi-purpose Internet Mail Extensions, is a freely available
specification that offers a way to interchange text in languages with
different character sets, and multi-media email among many different
computer systems that use Internet mail standards.

If you were bored with plain text email messages, thanks to MIME you
now can create and read email messages containing these things:

        - character sets other than ASCII
        - enriched text
        - images
        - sounds
        - other messages (reliably encapsulated)
        - tar files
        - PostScript
        - FTPable file pointers
        - other stuff

MIME supports not only several pre-defined types of non-textual
message contents, such as 8-bit 8000Hz-sampled mu-LAW audio, GIF image
files, and PostScript programs, but also permits you to define your
own types of message parts.

The ability to create email messages with audio and other non-textual
contents has been around for a while, but almost always as part of a
vendor-specific ``solution.''  This means that you can't create a
message on a NeXT system containing PostScript information and ``Lip
Service'' (NeXT's audio email tool) and easily handle the same
message on an HP 9000/710, a Sun SPARCstation IPC, and a Silicon
Graphics Iris.  That's a problem that MIME helps to solve.

One of the best things about MIME is that it's a "four-wheel drive
protocol", to borrow a description of PhoneNet from Einar Stefferud.
MIME was carefully designed to survive many of the most bizarre
variations of SMTP, UUCP, and Procrustean mail transport protocols,
such as BITNET and MMDF, that like to slice, dice, and stretch the
headers and bodies of email messages.

Here are a couple of examples of how MIME is being used in the real
world, now.

1) Dr Marshall T. Rose mails out his SNMP-related newsletter, ``The
Simple Times'' as multi-media email messages in several forms:

        - in a PostScript form, with beautiful typesetting and a
          two-column page layout, suitable for printing on a laser
          printer;

        - in a ``text/enriched'' form (explained in question 5.2), suitable
          for display on a mildly intelligent ASCII terminal; and

        - in a plain text, ordinary message form.

(SNMP is the Simple Network Management Protocol, a low-level network
management facility.)

2) IETF document announcements (RFCs, Internet Drafts, etc.) are
structured as multipart MIME messages.  The first part contains the
document abstract.  The second part is itself a multipart message,
containing external references to the document itself (one via a
mail-server, one via anonymous FTP).  Thus, with a suitable UA, you
can read the abstract, and then have the complete document retrieved
for you (by the most appropriate method) at the press of a button.


2.2 MIME features that may or may not be present

Implementations of multi-media email need not support the full spec;
it's possible to have a useful product that does not explore all of
the nooks and crannies of the standard.

Furthermore, MIME permits a message to contain alternative parts for
consumption by sites that can't necessarily display or listen to all
the good stuff.

Here is a list of features that someone with a good, functional
mail user agent might include for MIME support.

- Displays GIF, JPEG, and PBM encoded images, using e.g. 'xv' in the X
  Window System, or (name of windows program here) in Microsoft Windows.

- Displays PostScript parts, using e.g. something that prints to a
  PostScript printer, or that invokes GhostScript on an X Window System
  display, or that uses Display PostScript.

- Obtains external body parts via Internet FTP or via mail server.

- Plays audio parts on workstations that support digital audio.

On the other hand, the minimal requirements for a MIME-conformant MUA
are almost trivial, yet still provide increased funtionality.  (The
minimal requirements are mainly concerned with ensuring that users are
not shown raw data from a MIME message inappropriately.)


2.3 Further information

        adad.premenos.sf.ca.us:pub/mime.ps
        adad.premenos.sf.ca.us:pub/mime.txt

This is a nice overview of the MIME specification.

/* Any other documents that should be referenced? */


2.4 MIME glossary

Every subculture needs its list of buzzwords, here's a start at a
collection for MIME.

body            the part of a message after the header (the "meat")
ESMTP           Extended SMTP - RFC 1425
external part   a "pointer" to a part available via FTP or other means.
GIF             graphical interchange format for images
header          the To, From, Subject, etc. at the start of a message
JPEG            an image compression standard for still images
mail transport  the "post office", e.g. sendmail, smail, MMDF, etc.
MIME            Multipurpose Internet Mail Extensions - RFC 1341
MPEG            an image compression standard for moving pictures
MTA             Mail Transport Agent, see "mail transport"
MUA             Mail User Agent, see "user agent"
multi-media     nebulous marketroid term meaning audio and visual stuff
part            a piece of a MIME message containing some data type
PBM             an image format
PEM             Privacy Enhanced Mail
PostScript      a popular page description language
RFC             request for comments; proposed or standard Internet protocols
SMTP            Simple Mail Transport Protocol - RFC 821
text/enriched   simple text markup language for MIME
text/simplemail another (even simpler?) text markup language
user agent      the end user's mail program, e.g. MH, ELM, /bin/mail, etc.


2.5 MIME-relevant RFCs and other standards

The RFCs mentioned here are mainly relevant to people building MIME
software.  As an end user, if your mail system is nice to you, you
won't really have to know very much about these things.

RFC and Internet-Drafts are available by anonymous FTP from any decent
archive site.

MIME is defined in RFC 1341 (MIME Mechanisms for Specifying and
Describing the Format of Internet Message Bodies) and RFC 1342
(Representation of Non-ASCII Text in Internet Message Headers).

These are Internet standards-track protocols.  For the full
implications of this, see RFC 1410 (IAB Official Protocol Standards).
Here is their current status.

    1341: Proposed Elective Standard
    Latest draft: draft-ietf-822ext-mime2-04.txt, .ps

    1342: Proposed Elective Standard
    Latest draft: draft-ietf-822ext-mime-part2-01.txt

These two RFCs do not fully define MIME.  For one thing, they are
based on RFC 822 (Standard for the format of ARPA Internet text
messages), as revised by RFC 1123 (Requirements for Internet hosts -
application and support) and must be read in conjunction with these.

For another, they are extensible.  See 2.6 for a complete list of
registered subtypes.

There are a whole lot of other RFCs that deal with email, including
these.

    1468  Japanese Character Encoding for Internet Messages.
    1428  Transition of Internet Mail from Just-Send-8 to 8bit-SMTP/MIME.
    1427  SMTP Service Extension for Message Size Declaration.
    1426  SMTP Service Extension for 8bit-MIMEtransport.
    1425  SMTP Service Extensions.
    1424  Privacy Enhancement for Internet Electronic Mail: Part IV.
    1423  Privacy Enhancement for Internet Electronic Mail: Part III.
    1422  Privacy Enhancement for Internet Electronic Mail: Part II.
    1421  Privacy Enhancement for Internet Electronic Mail: Part I.
    1357  Format for emailing bibliographic records.
    1345  Character Mnemonics & Character Sets.
    1344  Implications of MIME for Internet mail gateways.
    1343  User agent configuration mechanism for multimedia mail format
          information.
    1339  Remote mail checking protocol.
    1327  Mapping between X.400(1988)/ISO 10021 and RFC 822.
    1321  MD5 Message-Digest algorithm.
    1314  File format for the exchange of images in the Internet.
    1225  Post Office Protocol: Version 3.
    1211  Problems with the maintenance of large mailing lists.
    1176  Interactive Mail Access Protocol: Version 2.
    1153  Digest message format.
    1036  Standard for interchange of USENET messages.

Older pre-MIME efforts at Internet multimedia email (largely of
historical interest).

    1197  Using ODA for translating multimedia information.
    1154  Encoding header field for internet messages.
    1049  Content-type header field for Internet messages.
    934   Proposed standard for message encapsulation.
    807   Multimedia mail meeting notes.


2.6 List of registered MIME types

    [ Joyce Reynolds <[e-mail]> 11-Jun-93 ]

    MIME TYPES

    RFC-1341 [169] specifies that Content Types, Content Subtypes,
    Character Sets, Access Types, and Conversion values for MIME mail
    will be assigned and listed by the IANA.

    Content Types and Subtypes
    --------------------------

    Type            Subtype         Description                 Reference
    ----            -------         -----------                 ---------
    text            plain                                       [169,NSB]
                    richtext                                    [169,NSB]

    multipart       mixed                                       [169,NSB]
                    alternative                                 [169,NSB]
                    digest                                      [169,NSB]
                    parallel                                    [169,NSB]

    message         rfc822                                      [169,NSB]
                    partial                                     [169,NSB]
                    external-body                               [169,NSB]

    application     octet-stream                                [169,NSB]
                    postscript                                  [169,NSB]
                    oda                                         [169,NSB]
                    atomicmail                           [atomicmail,NSB]
                    andrew-inset                       [andrew-inset,NSB]
                    slate                           [slate,terry crowley]
                    wita              [Wang Info Transfer,Larry Campbell]
                    dec-dx            [Digital Doc Trans, Larry Campbell]
                    dca-rft        [IBM Doc Content Arch, Larry Campbell]
                    activemail                             [Ehud Shapiro]

    image           jpeg                                        [169,NSB]
                    gif                                         [169,NSB]
                    ief             Image Exchange Format      [RFC-1314]

    audio           basic                                       [169,NSB]

    video           mpeg                                        [169,NSB]


2.7 Internet Engineering Task Force (IETF) working groups

    [ Ran Atkinson <[e-mail]> 2-Jan-1993 ]

    The IETF working group (ietf-smtp) on extensions to SMTP, which has
    essentially completed its work, is defining SMTP extensions
    including a safe and interoperable means for sending 8-bit wide data
    between two enhanced-SMTP systems.  This work was careful to avoid
    the "just send 8 bits without warning" mentality that is known to
    crash certain older SMTP-based systems.

    The IETF working group on Privacy-Enhanced Mail (PEM) is developing
    extensions that permit confidentiality, authentication, and
    integrity to be provided in a manner backwards compatible with
    RFC-821 and RFC-822.  Work is currently underway to integrate the
    PEM work with the MIME work.  Several implementations of PEM have
    been made available either commercially or without cost.  A PEM
    implementation developed by Trusted Information Systems, Inc. (TIS)
    under DARPA contract is available at no cost to most people and
    organizations in the US and Canada.  Implementations are known to
    exist outside of North America, though their availability to the
    public is not immediately known.  Interested parties should read
    comp.security.misc for more on PEM work.

    The IETF MIME working group is not actively considering significant
    changes to the specifications.  However the WG still exists as a
    forum for MIME developers, as a home for interpretation questions,
    and to handle any problems or ambiguities that might arise in MIME.


2.8 Newsgroups and mailing lists

You're probably reading comp.mail.mime at the moment.  There is a
mailing list which is gatewayed with comp.mail.mime.  If you are
unable or unwilling to read Usenet news, send subscription requests to:

        [e-mail]

There is also a [comp.mail.multi-media] newsgroup, which contains
general discussions of multi-media email, not necessarily MIME.

There are various mailing lists specific to particular implementations
of MIME.  If I know of such a list, it is mentioned in the section on
that implementation.


3 Freely available MIME software packages

3.1 metamail

        thumper.bellcore.com:pub/nsb/mm.2.5.tar.Z
    The metamail distribution that Nathaniel Borenstein supports.

        thumper.bellcore.com:pub/nsb/contrib2.5.tar.Z
    Contributed sources.

        thumper.bellcore.com:pub/nsb/amiga2.5.tar
    Amiga binaries and utilities

        thumper.bellcore.com:pub/nsb/dos2.5.tar.Z
    DOS binaries

    [ Paul Eggert <[e-mail]> ]

    Metamail is a software implementation of MIME, designed for easy
    integration with traditional mail-reading interfaces -- typically,
    users do not invoke metamail directly.  Ideally, extending the
    local email or news system to handle a new media format is a
    simple matter of adding a line to a mailcap file.  Mailcap files
    are described in RFC 1343.


3.2 MIXMH

    [ Harald Tveit Alvestrand <[e-mail]> 10-Dec-1992 ]

        aun.uninett.no:pub/unix/mixmh-0.2.tar.Z

    This version is based on XMH version 1.6 from SEI, Carnegie Mellon.
    It supports sending MIME with extended character sets in the headers
    (per RFC-1342) and the body (per RFC-1341 text/plain).  It has
    limited support for multipart messages.

    The source is freely redistributable and modifiable.

    As you can see from the version number, it is still not considered
    fully stable. Bugs may be reported to [e-mail]
    Information and discussion will take place on [e-mail];
    mail to [e-mail] to join.


3.3 MH 6.8 and 'mhn'

        ftp.ics.uci.edu:pub/mh/mh-6.8.tar.Z
        louie.udel.edu:portal/mh-6.8.tar.Z

MIME support is available for the MH message handling system; the
primary reader and generator is the program mhn(1) although other MH
programs are also changed.  The current release of MH is 6.8, the first
to include MIME support when appropriately installed.  Note that mhn is
not compliant with RFC 1343.

A tutorial for mhn is available:

        ftp.ics.uci.edu:mh/contrib/multimedia/mhn-tutorial.tex, .sty, .ps

See the newsgroup comp.mail.mh for further information.


3.4 Pine

Pine: Authors Laurence Lundblade, Michael Seibel, and Mark Crispin
     <[e-mail]>

    [ comp.mail.misc FAQ ]

    Pine is a mail user agent developed by the University of
    Washington Office of Computing and Communications. It has been
    designed for ease-of-use and with the novice computer user in
    mind. It is based on Internet mail protocols (e.g. RFC-822, SMTP,
    IMAP, and MIME) and currently runs on a variety of UNIX platforms
    and MS-DOS.

    The guiding principles for achieving ease-of-use in Pine were:
    careful limitation of features, one-character mnemonic commands,
    always-present command menus, immediate user feedback, and high
    tolerance for user mistakes.  It is intended that Pine can be
    learned by exploration rather than reading manuals.

    A stand-alone version of Pico, Pine's message composition editor,
    is also available.  It is a very simple and easy to use text
    editor with text justification and a spelling checker.

    Features:
       - Mail index showing a message summary which includes the
         status, sender, size, date and subject of messages.

       - View and process mail with the following commands:  forward,
         reply, save, export, print, delete, capture address and
         search.

       - Address book for saving long complex addresses and personal
         distribution lists under a nickname.

       - Multiple folders and folder management screen for filing
         messages.

       - Message composer with easy-to-use editor and spelling checker.
         The message composer also assists entering and formatting
         addresses and provides direct access to the address book.

       - Online help specific to each screen and context.

       - Supports access to remote mail repositories via the IMAP2
         protocol defined in RFC-1176.

       - Supports multi-part mail conforming to MIME allowing sending
         of sounds, graphics such as GIF and TIFF files, and binary
         files such as spreadsheets.

    Pine, including source code, is freely available via anonymous FTP
    from ftp.cac.washington.edu on the Internet. Other provisions for
    distribution have not yet been made. From the Internet, you may
    try out Pine and leave comments by telneting to
    demo.cac.washington.edu and logging in as "pinedemo". To join the
    Pine mailing list for announcements send a request to
    "[e-mail]".

    Pine is very portable and runs on a variety of UNIX machines
    including DECstations, NeXTs, VAX's and Suns. Pine was originally
    based on Elm, but it has evolved much since, ("Pine Is No-longer
    Elm").  Pine uses the c-client library discussed below.

    For further information send email to [e-mail].
    Pine is the work of Mike Siebel, Mark Crispin, and Laurence
    Lundblade at the University of Washington.


3.5 c-client

    [ comp.mail.misc FAQ ]

    Software writers only:

    c-client is a general library useful for creating MUA's.  It
    provides a Application Program Interface for retrieving and
    manipulating mail messages.  It supports the latest draft of
    MIME.  It is driver based, and easily ported to new platforms and
    MTAs.  The currently supported platforms include various versions
    of BSD and SysV Unix, DOS, Macintosh and even TOPS-20(!).  It
    supports mailboxes in /usr/spool/mail, mbox, mail.txt, mh, carmel
    format, as well as remote mailbox access via the IMAP2 protocol
    described in RFC-1176 and extended by the IMAP2bis extensions.

    c-client does not contain any user interface.  Rather, it contains
    everything else that goes into an MUA.  c-client is called with
    such functions as mail_open(), mail_fetchheader(), mail_setflag(),
    etc.

    Just the thing if you want to write a new MUA.

    Contact the author (Mark Crispin <[e-mail]>) for more details.


3.6 Andrew

    [ Susan Straub <[e-mail]> 11-Jan-1993 ]

    Andrew is a very large and ambitious software system developed at
    Carnegie Mellon University.  It is installed at hundreds of sites
    throughout the world, and includes a multimedia document editor,
    help system, and various other utilities.  In particular, it
    includes a feature-rich program, "messages", which can read and
    send mail and news articles in MIME format, including images,
    audio, richtext, and more.  Andrew is available in binary release
    for several UNIX system architectures, and also in source form.
    Be warned that the source distribution is itself about 50
    megabytes, but you really are getting a LOT of stuff.  For
    information on how to obtain a copy of Andrew, send mail to
    [e-mail].


3.7 elm

    [ Syd Weinstein <[e-mail]> 21-Dec-1992 ]

    Elm support for MIME:
    2.3 - uses metamail supplied patch from Nathaniel Borenstein.

    2.4:
        reading: detects MIME headers and calls metamail automatically
        if the message cannot be displayed on the current screen using
        the native capabilities of the display (recognizes some char
        sets as native)

        sending: detects [include ] markers and makes them MIME attachments.
        Still very 'crude', but its all we had time for, as to the
        release deadline of 'Elm' and MIME.

    3.x:
        reading: probably no change from 2.x, but will understand
        some 'file storage' types and allow for splitting off attachments
        on their own.

        sending: will allow defining attachments to be added and auto build
        the MIME stuff, in addition to the [include ] syntax.

    release status:
    2.3: obsolete
    2.4: Current PL is 17.
    3.x: not planned until some time in 1994.


3.8 MIME tools for NeXT

    [ Dave Lacey <[e-mail]> ]

    I'd like to keep you apprised of some MIME work I'm doing.  I'm
    interested in using MIME as a transport medium for multi-media
    gopher documents.  My particular use is for Radiology info, but it
    would work for just about anything.

    I've got a NeXT Gopher client almost working and I also have a
    NeXT based MIME file editor that reads/creates MIME documents.
    Both work, but need a bit more extension.  I will likely
    distribute the source to this, so the MIME reader (which is
    essentially an object) can be re-used in other apps.


3.9 Conversions from other mail systems

A number of older email systems have defined ad hoc ways of dealing
with binary file enclosures and multipart messages.  This section is a
pointer to some tools that would aid in transition efforts to the
standard MIME approach.


3.9.1 uuencode to MIME

    [ Keith Moore <[e-mail]> 30-Dec-1992 ]

        cs.utk.edu:pub/MIME/uu-to-mime.perl

    A perl script that translates an RFC 822 message containing a single
    uuencoded file to a MIME message containing a base64-encoded file.


3.9.2 Sun OpenWindows mail to MIME

    [ Keith Moore <[e-mail]> 27-Dec-1992 ]

        cs.utk.edu:pub/MIME/sun-to-mime.perl
        cs.utk.edu:pub/MIME/sun-to-mime.c

    A perl script (and conversion to C of same) that converts
    OpenWindows mail to MIME.  Body parts currently supported are:
    text, gif, Sun rasterfile (converted to image/gif), postscript,
    and audio.  Other types default to application/octet-stream.  It's
    easy to extend the set of types supported and to add conversions,
    if necessary.

    The script requires uuencode, uudecode, zcat (aka uncompress), and
    the "convert" program from ImageMagick.  If you don't have
    ImageMagick you can probably substitute the pbm stuff with little
    fuss.


3.9.3 NeXTmail to MIME

/* Are these two talking about the same thing? */

    [ Dave Curry <[e-mail]> 26-Dec-1992 ]

    An external program to convert it to MIME is easy...  I did one for
    NeXT-to-MIME (n2m), and that's a fairly hard transformation.

    I wonder if I should post it...  (I wonder if I did post it (:-()

    [ Dave Collier-Brown <[e-mail]> 04-Jan-1993 ]

        nexus.yorku.ca:pub/n2m.shar

    Nn2m is a program that converts a file containing a NeXT-format
    multimedia message into a file containing a MIME-format multimedia
    message.

    It is usable on Berkeley-derived systems, or ones otherwise using
    /usr/lib/sendmail as a mail transfer agent. It is in use on SunOS
    4.1.1 and Ultrix 4.2, tested briefly on Aix 3.2 and NeXT.

    Description: it is used with non-NeXT mail user agents to convert
    NeXT mail to MIME, which is intelligible to more than just the
    NeXT mail program.  The resulting file will usually be more
    intelligible to non-multimedia mail user agents.

    The textual part of the mail is converted into text, as well as
    Microsoft RTF, and the attachments follow, as text/plain wherever
    possible, as base64 encoded binaries otherwise.  This suffices for
    messages with ASCII files pasted into them.

    Caveat:  This is a converter, not a translator: the conversion of
    sound and of the initial ``index.rft'' file is not correctness-
    preserving.


3.10 MIME for VMS MAIL (HUyMailer)

    [ Yehavi Bourvine <[e-mail]> 22-Dec-1992 ]

    >Is there any public domain package that does MIME for VMS MAIL?

    I am working on adding it to my HUyMailer. I've started it but had
    to abandon it for a while. I hope next month (which is also the
    next year, eh?) I'll be able to continue working on it.


4 Commercial MIME software packages

4.1 IBM multimedia mail for OS/2

    [ Larry Salomon Jr <[e-mail]> 10-Dec-1992 ]

    I'm not going to follow this group, but I wanted to state that IBM
    - at the T.J. Watson Research Center - is developing a multimedia
    mail application for OS/2 which is based on the Mime spec.  They
    demoed it at Interop.

    For more information, including (probably) how to become a test
    site (I haven't confirmed whether they're actually going to do
    this, but they've done it before), contact the department manager,
    Jerry Cuomo, at [e-mail]


4.2 Innosoft PMDF for VMS

The VMSNET newsgroup 'vmsnet.mail.pmdf' is available for discussion.

    [ Ned Freed <[e-mail]> ]

    Send technical inquiries to [e-mail]. Product
    information, pricing, and literature can be obtained from
    [e-mail]. The phone number is [phone]; FAX is
    [phone]. Street address is:

        Innosoft International, Inc.
        250 W. First St., Suite 240
        Claremont, CA 91711


4.3 Control Data Systems Mail*Hub package

    [ <[e-mail]> 23-Dec-1992 ]

    Mail*Hub includes support for X.400, X.500, SMTP, and creating,
    viewing, and sending MIME enclosures in mail. In addition, the Fax
    Gateway portion of Mail*Hub supports sending mail with MIME
    enclosures to a Fax machine.  Graphical MIME components
    (Postscript, GIF, TIFF,...)  are automatically recognized and
    imaged at the receiving Fax machine.

    The product is shipping now and is currently available on Control
    Data 4000 Series Mips-based Unix systems. For more information
    contact [e-mail]


4.4 cc:MAIL support for MIME

SMTPLINK 2.1 will support MIME.

    [ <[e-mail]> 16-Dec-1992 ]

    Because this version (2.1) is a 2-3 QTR-93 release you should be
    talking to your sales rep about the tentative features of this
    product. They can be reached at 800-448-2500.


4.5 Z-code Z-Mail

    [ Carlyn M. Lowery <[e-mail]> 29-May-1993 ]

    Z-Mail, a UNIX World Magazine "Product of the Year" winner for
    1991, is a complete electronic mail system for workstations.
    Z-Mail provides Motif and Open Look graphical user interfaces, as
    well as two character modes.  The software has been ported to
    nearly every system that runs UNIX, and it works with all standard
    UNIX mail transport agents including sendmail, binmail, smail,
    MMDF and X.400 gateways.  Z-Mail can replace or coexist with
    standard mail user agents on the system, including BSD Mail, AT&T
    mailx, Sun Mail Tool, Elm, or Mush.  Most anyone can use Z-Mail
    "off the shelf" and immediately benefit from its simple interface
    and advanced features.

    Z-Mail also includes Z-Script, a powerful scripting language that
    enables users to customize and extend Z-Mail's capabilities.
    Z-Mail's multi-media capabilities allow easy integration with
    best-of-class products including spreadsheets, desk-top
    publishing, graphics, fax, voice, and video. For example, when
    users receive a spreadsheet file, Z-Mail can be configured to
    automatically launch the associated application and load the the
    attachment automatically and transparently to the user.  Z-Mail
    understands MIME-format documents and is also compatible with
    Sun's multimedia Mailtool.

    Mac, DOS, and Windows versions, as well as native MIME support, are
    planned for this summer.

    For more information on Z-Mail, contact:
        Z-Code Software Corp.
        4340 Redwood Hwy., Suite B-50
        San Rafael, CA 94903
        tel: [phone]
        fax: [phone]
        e-mail: [e-mail]

    Also, you can anonymous-ftp a demo copy of Z-Mail from "ora.com" in
    the directory pub/z-code/zmail/2.1.  (The file you want is named
    zm.XXX.tar.Z, where XXX is your type of machine.)  You'll need to
    call us after you do so we can send you an activation key.


4.6 STI Document Browser

    [ Ed Anselmo <[e-mail]> 31-Dec-1992 ]

    Product name:   STI Document Browser
    Platforms:      Windows 3.1 (shipping), NeXTstep/X11/VMS (in the
    pipeline)
    How and where to get:
        Stream Technologies Inc.
        Valkjarventie 2
        SF-02130 Espoo
        FINLAND
        Tel: [phone]
        Fax: [phone]
        Email: [e-mail]


4.7 Frontier Technologies Super-TCP mail system

    [ Ray C Langford <[e-mail]> 28-Apr-1993 ]

    Frontier Technologies' Super-TCP for Windows includes MIME support
    in their Email mail system that is a part of the Super-TCP for
    Windows package.

    Super-TCP for Windows is a Windows Sockets compliant, 100% DLL
    implementation that can also operate in a TSR mode. Applications
    include: Network News Reader, Telnet, FTP Client/Server, NFS
    Client/Server, SMTP/POP2&3 MIME Email, Telnet Redirector,
    Interactive Talk, and more. Options are also available for PPP,
    X.25, and OSI.

    With the MIME support in Email, any type of binary file may be
    attached to your message, including Postscript files, spreadsheet
    files, database files, word processor files, graphic files, audio
    files, and digital video files.

    The packages in the Super-TCP product line that include the
    Email (SMTP/POP2&3) with MIME support are:
        - Super-TCP for Windows   Version 3.0
                (Complete TCP/IP package)
        - Super-TCP/NFS for Windows   Version 3.0
                (Complete TCP/IP package with NFS client/server)
        - Super-TCP Applications for Windows   Version 3.0
                (Windows Sockets applications only)

    For further information, email [e-mail] or call
    [phone].


4.8 PP

PP is a Mail Transport Agent (MTA), kindof son-of-MMDF-plus-X.400.  It
is built on ISODE.

    [ Harald Alvestrand <[e-mail]> 18-Dec-1992 ]

    The ISODE Consortium release of PP will in the near future support
    gatewaying between MIME and X.400 according to the MIME-MHS
    Internet-Drafts.

It will also support ESMTP.


4.9 HP's MPOWER

    [ Harald Alvestrand <[e-mail]> 22-Jan-1993 ]

    If anyone is interested, the new multimedia product from HP called
    MPOWER supports MIME format mail.

    You can drag and drop a picture onto the mail icon, and it will be
    sent as a MIME message.

    (Unfortunately, they forgot to quote the delimiter that had a dot
    in it, and PINE failed to parse that......well, it's a betatest.)


5 Miscellaneous questions

5.1 What can I use to display MIME messages?

You need something that understands MIME-structured messages and also
understands how to display the different kinds of body parts.

Details of many freely available and commercial packages to do just
that can be found in sections 3 and 4 of this FAQ.


5.2 What's "text/enriched"?  "text/simplemail"?

These two subtypes of the "text" type have a similar aim: to offer
simple text markup, without making the text unreadable to someone
without the software to interpret it.

The text/enriched scheme uses markup commands enclosed in angle
brackets.  For example, here is how you would <bold>embolden</bold> a
single word.

Simplemail is more like a standardisation of certain existing
practices in mail and news articles.  For example, here is how you
would *emphasize* a single word.

The text/enriched type supersedes "text/richtext" that was defined in
RFC 1341.  The latter is now obsolete.  The text/enriched type is
defined in an Internet Draft, the latest version of which is

    draft-ietf-822ext-text-enriched-00.ps, .txt

/* Is simplemail an Internet Draft yet? */


5.3 What about security issues?

Both users and administrators should be aware that ordinary Internet
and UUCP email is not secure.  No authentication, confidentiality, or
data integrity properties are provided in SMTP, RFC-822, or MIME.
People desiring any or all of those security properties in their email
should look into the use of Privacy-Enhanced Mail (PEM).  At least one
no-cost implementation of PEM is available in the US and Canada.

A system providing similar functionality to PEM implementations is
PGP.  PGP is an implementation, not a specification, and it does not
carry the blessing of the IETF, or any other body.  It is, however,
available at no cost throughout the world (although its status with
respect to certain US patents is dubious).  Caveat emptor.


5.4 So, does MIME introduce any new security problems?

Yes.  MIME user agents can do previously unheard of things with mail
messages, notably giving them as input to other programs.

PostScript is probably the biggest potential security hole.  One
famous example is the "melting screen" PostScript program, which
destroys screens maintained by Display PostScript implementations.
For another example, PostScript can be used to change the password on
some PostScript printers with previously undefined passwords, which
denies the use of the printer until the printer's password can
(somehow) be changed back.  Yet other Display PostScript
implementations may allow file operations.  (NeXTstep wisely disables
file operations.  With GhostScript, they can be disabled by the
"-dSAFER" command line option.  Use of this option (in mailcap, etc.)
is highly recommended.)

The enumeration of these security holes is not to be interpreted as
encouragement to exploit the holes.  They are mentioned only because
they are well known.  Refer to books such as "Practical UNIX Security"
and to news groups such as comp.security.misc for general information
about system security.


5.5 What about a group 3 facsimile encoding?

/* This section needs some work - any volunteers? */

It is rumored that there was an attempt to include G3 FAX in the
current MIME standard, but that it was impossible for the authors of
the MIME specification to gain a consensus on how to encode the data.
So G3 FAX has been left for a future MIME implementation.  But you can
always define your own body part.

Here are some snippets relevant to MIME and FAX.

The MIME-MHS documents define a G3Fax body part that is conformant with
the X.400 G3Fax definition.

    [ Stuart Lynne <[e-mail]> 30-Dec-1992 ]

    I have prototype scripts operating with metamail to do some of this.
    Some of it is in contrib directory.

    Currently I have 2 scripts:

        mm2fax  - convert mail and metamail messages to TIFF/F (uses various
        tools to convert different body parts to TIFF/F);

        faxmm   - send rfc822 and mime email messages via facsimile (uses
        mm2fax to convert to TIFF/F).

    [ Ned Freed <[e-mail]> 31-Dec-1992 ]

    PMDF-FAX is a set of channel programs for PMDF that provide
    facilities for converting text, PostScript, and various other
    formats into Group 3 FAX, as well as a set of programs that take
    these Group 3 FAX files and use them to drive a variety of FAX
    modems.  MIME is used throughout to provide type information,
    multipart facilities, and so forth. PMDF-FAX was developed with MIME
    in mind from the outset.


5.6 Should I always use external body parts to save space?

Not necessarily.  In many cases, for example, at the ends of UUCP
connections, your recipients may not be able to retrieve external body
parts easily.  It depends on your audience.  Making files available via
a mail server is to be encouraged.  It is always possible to provide
MIME alternative parts that first offer FTP, then mail server options.


5.7 What mail servers can I reference?

There are various mail servers available.  Check news.answers for the
FAQ about mail server software.  We do not presently have a
recommendation.


5.8 How can I register a new MIME type?

The procedures for registering new content types, character set
values, access types, and conversions parameters with IANA (the
Internet Assigned Numbers Authority) are documented in RFC 1341.


5.9 What's ESMTP, and how does it affect MIME?

ESMTP (Extended Simple Mail Transfer Protocol) is a mechanism by which
extensions to "traditional" (RFC 821) SMTP can be negotiated by client
and server.  The mechanism (RFC 1425) is open-ended; so far two
extensions have been defined.

Message size declaration (RFC 1427) offers a graceful way for servers
to limit the size of message they are prepared to accept.  (With SMTP,
the only possibility is for the server to discard the message after it
has been sent in its entirety.  There is no way for the client to know
that it was the size of the message that caused the problem.)  The
obvious way for a client to cope with the situation of a message which
is too large to be accepted is to fragment the message using the MIME
Message/Partial mechanism.

8bit-MIMEtransport (RFC 1426) opens up the possibility of sending 8bit
data in mail messages, without having to use base64 or a similar
encoding.  RFC 1428 (Transition of Internet Mail from Just-Send-8 to
8bit-SMTP/MIME) discusses some of the implications of this.


6 MIME information available from the Internet

6.1 Anonymous FTP

Information about FTPable stuff is scattered throughout this FAQ.
More specifically, look into the RFCs, mentioned in item 2.4.  Other
goodies can be found in the MH and MetaMail source trees.

        thumper.bellcore.com:pub/nsb

contains a collection of MIME sample messages which can be used to
test implementations.


6.2 Mail based archive servers

6.2.1 Eitech "ServiceMail"

    [ Jay C. Weber <[e-mail]> 13-Oct-1992 ]

    We (Enterprise Integration Technologies Corporation) have a MIME
    implementation, which we are distributing freely.  Instead of a
    MIME MUA, it is a toolkit for building services that automatically
    process MIME messages.  It is similar, in spirit, to the few other
    email-scripting packages except:

      o it exploits several MIME features
      o it is intended to run standalone (as opposed to a back-end to a MUA)
      o it uses TCL (from Berkeley) as its scripting language

    and support for PEM is in the works.

    EIT is providing ServiceMail access to the ServiceMail toolkit.
    If you have the METAMAIL or some other MIME-compliant mail reader,
    just send the message

        To: [e-mail]
        Subject: archive-request servicemail.tar.Z

    and read the response(s) using METAMAIL.  Save the result in
    servicemail.tar.Z

    The package can also be retrieved by anonymous FTP from the site
    eitech.com.

    If you have any problems with acquisition, installation, or use,
    don't hesitate to send mail to "[e-mail]" and
    ask for help.

    IF YOU WANT FUTURE UPDATES ON TOOL KIT VERSIONS, BUGS, AND
    SERVICES, MAKE SURE YOU ARE ON THE PACT-KIT MAILING LIST.  To get
    on it, send a message to "[e-mail]" with subject
    "listserv subscribe pact-kit your-real-name".


6.2.2 Metamail "mailserver"

    [ Nathaniel Borenstein <[e-mail]> 9-Jan-1993 ]

    The metamail distribution includes a simple "mailserver" shell
    script that can be used to operate a MIME-conformant mail server
    mechanism, e.g. for making anon-ftp files available as MIME mail.
    ServiceMail is also now available under the "contrib" area of the
    metamail distribution.


6.3 Gopher

    [ Randall Atkinson <[e-mail]> 2-Jan-1993 ]

    There is experimental work underway in the Internet Gopher community
    to include MIME as a mechanism for marking the content of files.
    The freely distributable Gopher client for NeXTstep 3.0 includes
    MIME support.  Other gopher clients will probably add it eventually.


/* Any info on WAIS, CD-ROM, etc? */


7 Published books and articles

Published books or articles that cover MIME.

Marshall T. Rose has recently published the fourth book in his
networking "trilogy".

    Marshall T. Rose
    "The Internet Message: closing the book with electronic mail"
    Prentice-Hall
    ISBN 0-13-092941-7

It is a reasonably complete, although not technically detailed, review
of the Internet world of electronic mail, including recent
developments.  One chapter is devoted to MIME (be warned that events
have moved on since the publication of this book, and some of the
detail in this chapter is no longer accurate).


    [ Alec Henderson <[e-mail]> 18-Dec-1992 ]

    There is a good introductory article on MIME in the September 1992
    issue of Connexions; also several other interesting articles on
    email, both MIME and X.400.  (Ole Jacobsen, the Connexions
    editor, was kind enough to send me a copy of the September issue.)


8 MIME based relays for commercial mail services

8.1 Large national or international providers

/* Lots missing here.  Anyone got any info these, or any others?

    America On-line
    Compuserve
    Dialog
    Genie
    MCI Mail
    Sprintmail
 */

8.1.1 ATTMAIL

    [ Steve <[e-mail]> 30-Dec-1992]

    We do support binary attachment but are not MIME compliant nor do
    we have an X.400 to MIME conversion header routine. This is 'in the
    works', however, and due to overwhelming interest by our users and
    other prmd's, research and development are currently engaged in
    working on the issue. I do not have any information on when this
    will be available, but will let you know when I receive word of our
    MIME status.


8.1.2 Radiomail

    [ Jerry Sweet <[e-mail]> 17-Dec-1992 ]

    RadioMail Corp. (formerly Anterior Technology) operates three types
    of email services having these statuses with respect to MIME:

    1. UUCP/Internet gatewaying.  The gateway passes MIME messages using
    7 bit encodings in either direction.  The sender and receiver must,
    of course, have MIME-complaint user agents in order to handle MIME
    email.

    2. cc:Mail/Internet gatewaying.  cc:Mail does permit binary
    attachments of various types, and these attachments are encoded by
    the gateway for transfer via SMTP, but the encoding is not presently
    MIME compliant.  This may change.

    3. Wireless email gatewaying.  This service can pass MIME messages
    using 7-bit encodings in either direction.  However, MIME per se is
    understood neither by the DOS-hosted user agents presently supplied
    by RadioMail Corp. for use on radio modem equipped computers, nor by
    any RadioMail-compatible third-party DOS-hosted user agents.  This
    may change.

/* Should coordinate this with the global email list that is posted to
   comp.mail.misc.
 */


8.2 Local and regional providers

/* Any info?  Should coordinate this with e.g. the PDIAL list */


9 MIME and Usenet news

9.1 Introduction

Usenet articles are (by design) very similar to RFC 822 mail
messages.  It is therefore reasonable to expect MIME software to be
adopted for use on Usenet.


9.2 nn

    [ Luc Rooijakkers <[e-mail]> 04-Jan-1993 ]

    The next public nn release (scheduled for middle January,
    currently in its second beta) will tag newly posted articles as
    text/plain; charset=xxx with transfer encoding 8bit if the message
    contains any 8 bit characters.

    Reading support is being worked on by me, but won't be available
    for some time (say a few months).  Basic transfer decoding and/or
    character set support may be available earlier, but don't count on
    it.


9.3 GNUS

    [ Christopher Davis <[e-mail]> 03-Jun-1993 ]

    There is MIME support (using metamail) available for GNUS.  Contact
    [e-mail] for more details.


9.4 INN

    [ Christopher Davis <[e-mail]> 03-Jun-1993 ]

    There is some minimal MIME support in the INN package.  Since INN
    is a transport system, not a newsreader, the support is for
    transferring MIME messages, not reading them.


10 Acknowledgements

Many people have contributed to this document.

They include:

Harald Alvestrand, Ed Anselmo, Ran Atkinson, Jason Beyer, Nathaniel
Borenstein, Yehavi Bourvine, David Collier-Brown, Mark Crispin, Dave
Curry, Christopher Davis, Paul Eggert, Ned Freed, Alec Henderson, Dave
Lacey, Ray Langford, Carlyn Lowery, Stuart Lynne, Keith Moore, Rich
Ragan, Luc Rooijakkers, Marshall Rose, Larry Salomon Jr, Susan Straub,
Jerry Sweet, Erik van der Poel, Edward Vielmetti, Jay Weber, Syd
Weinstein.

If I've left your name off, please accept my apologies.  Drop me a
note and I'll include it for next time.

Tim.
--
Tim Goodwin | [e-mail]  or | OSI is now more of a problem than
PIPEX Ltd   | [e-mail] | a solution - Marshall T Rose.
--
Tim Goodwin | [e-mail]  or | OSI is now more of a problem than
PIPEX Ltd   | [e-mail] | a solution - Marshall T Rose.