comp.mail.mime frequently asked questions list (FAQ) Path: ulysse!enst!julienas!mcsun!uunet!pipex!pipex!not-for-mail From: tim@pipex.net (Tim Goodwin) Newsgroups: comp.mail.mime,comp.answers,news.answers Subject: comp.mail.mime frequently asked questions list (FAQ) 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. Message-ID: Date: 6 Aug 93 16:13:38 GMT Expires: 29 Sep 1993 16:13:34 GMT Followup-To: comp.mail.mime Organization: Pipex Ltd., 216 Science Park, Cambridge CB4 4WA, England Lines: 1467 Approved: news-answers-request@MIT.Edu Supersedes: Xref: ulysse comp.mail.mime:1294 comp.answers:1251 news.answers:9426 NNTP-Posting-Host: tank.pipex.net Archive-Name: mail/mime-faq Last-modified: 1993/07/22 Version: 2.7 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. Changes since the last version are marked by "!" in the index. I also post a seperate article containing diffs to comp.mail.mime. This FAQ 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 -- UNIX, Amiga, DOS MUA 3.2 MIXMH -- UNIX/X MUA 3.3 MH 6.8 -- UNIX MUA 3.4 Pine -- UNIX MUA 3.5 c-client 3.6 Andrew 3.7 elm -- UNIX MUA 3.8 MIME tools for NeXT ! 3.9 HUyMail -- VMS ? ! 3.10 MIME for VM/CMS ! 3.11 Iride -- Macintosh MUA ! 3.12 Eudora -- Macintosh MUA 3.13 Conversions from other mail systems 3.13.1 uuencode to MIME 3.13.2 Sun OpenWindows mail to MIME 3.13.3 NeXTmail to MIME 4 Commercial MIME software packages 4.1 IBM multimedia mail for OS/2 4.2 PMDF -- VMS ? 4.3 Control Data Systems Mail*Hub package 4.4 cc:MAIL support for MIME 4.5 Z-Mail -- UNIX MUA 4.6 STI Document Browser 4.7 Frontier Technologies Super-TCP mail system 4.8 PP -- UNIX MTA 4.9 HP's MPOWER ! 4.10 Eudora -- Macintosh MUA 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? ! 5.10 Where can I get some sample MIME messages? 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 ! 6.4 World Wide Web 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 ! 9.3 GNUS ! 9.4 trn ! 9.5 INN ! 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 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 2-Jan-1993 ] The IETF working group (ietf-smtp) on extensions to SMTP, which has essentially completed its work, has defined SMTP extensions including a safe and interoperable means for sending 8-bit wide data between two enhanced-SMTP systems (see 5.9). 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 (see 5.3). 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: info-mime-request@thumper.bellcore.com 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 -- UNIX, Amiga, DOS MUA thumper.bellcore.com:pub/nsb/mm.2.6.tar.Z The metamail distribution that Nathaniel Borenstein supports. thumper.bellcore.com:pub/nsb/contrib2.6.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 ] 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 -- UNIX/X MUA [ Harald Tveit Alvestrand 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 mixmh-bugs@uninett.no Information and discussion will take place on mixmh-info@uninett.no; mail to mixmh-info-request@uninett.no to join. 3.3 MH 6.8 -- UNIX MUA 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 -- UNIX MUA Pine: Authors Laurence Lundblade, Michael Seibel, and Mark Crispin [ 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 "pine-info-request@cac.washington.edu". 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 pine@cac.washington.edu. 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 ) for more details. 3.6 Andrew [ Susan Straub 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 info-andrew-request@andrew.cmu.edu. 3.7 elm -- UNIX MUA [ Syd Weinstein 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 ] 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 HUyMail -- VMS MTA/MUA [ Yehavi Bourvine 22-Jul-1993 ] vms.huji.ac.il:local/huymail*.bck HUyMailer is a store and forward mailer for VAX/VMS and AXP/VMS systems which supports as transports: DECnet, Multinet/TcpIp, HUJI-NJE and PMDF. The software is available freely for non-commercial use as a C source code. The mailer supports two users' interfaces: VMS/MAIL (to which the connection is done via MAIL11 DECnet connection) or a locally written interface called BMAIL. BMAIL is a menu oriented interface which supports MIME and Hebrew. 3.10 MIME for VM/CMS [ Rick Troth 21-Jul-1993 ] This MIME decoder is available via Gopher from ricevm1.rice.edu under "Other freely distributable CMS software", which is under "CMS Gopher Software". It correctly reads: o text/plain, o text/richtext, and o image/gif. GIFs require the VMGIF package from Belgium. I need filters for PBM and PGM and then they'd work too. Sounds are not useful on the standard 3270 terminal (dumb terminals just don't play sounds). It splits out multipart/[anything] into separate files. CMS has a standard directory "browser" (FILELIST) that lets you view a bunch ofrelated files and decide what, if anything, you want to do with them. Message/external-body doesn't work well, but probably will given more development time. I could use some samples to help with the debugging of that part. It does NOT do applications, except for the one, octet-stream. (which is treated as a kind-of "sendfile" utility) There *is* a PostScript interpreter for CMS, but it is reported to be a dog (we don't have it). But I do hope to put the extraction code in for these eventually. If a given content-type isn't understood, you just view the item as-is. For composition, there's no CHARSET= parameter on the Content-Type: text/plain line. It's EBCDIC until it gets into SMTP, then it's ASCII, then it might be anything, so I've left off the CHARSET= parameter. An "attach" command is added to RiceMAIL when you run this, which would then change the message from text/plain to multipart/mixed and append the attachment after a boundary. Attachments don't "close" properly; that is, the final boundary isn't correct, but is correctly processed by all of the MIME compliant readers I've checked. (there's some feature of RiceMAIL that causes this) This thing is based on CMS Pipelines, so adding features is easy since we now have the base for MIME processing. 3.11 Iride -- Macintosh MUA gnbts.univ.trieste.it:mime/Iride.sea.hqx [ From the README ] Iride is (or will be -- it's currently in beta test) an implementation of a MIME user agent on the Apple Macintosh computer. It was developed as part of a project of the GNBTS - Gruppo Nazionale Bioingegneria sezione di Trieste, for the integration of multimedia mail with hospital data storing facilities, in particular for the transfer of bioimages. This is a far from a complete MIME implementation, but I think it is quite usable. To use it you need: o Macintosh with MacTCP 1.1 or better installed o 32 bit ColorQuickDraw if you want to use images o audio input device if you want to create audio messages o connection to a SMTP mail relay o connection to a POP3 server MIME types supported: text/plain charset=US-ASCII only text/richtext (no tool for composing richtext yet) audio/basic audio/X-macaudio generated when a NOT sampled audio pasted in image/GIF image/X-macPICT generated when color QuickDraw is missing only multipart/mixed each part is shown in a different window MUST change this multipart/parallel multipart/alternative handled as multipart/mixed MUST change this 3.12 Eudora -- Macintosh MUA [ Ian Hoyle 29-Jun-1993 ] The next version (now in beta) will support MIME. Eudora is POP3-based. A commercial version with more bells and whistles is also available. Contact Steve Dorner for details. 3.13 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. 3.13.1 uuencode to MIME [ Keith Moore 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. 3.13.2 Sun OpenWindows mail to MIME [ Keith Moore 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. 3.13.3 NeXTmail to MIME /* Are these two talking about the same thing? */ [ Dave Curry 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 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. 4 Commercial MIME software packages 4.1 IBM multimedia mail for OS/2 [ Larry Salomon Jr 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 gcuomo@watson.ibm.com 4.2 PMDF -- VMS ? The VMSNET newsgroup 'vmsnet.mail.pmdf' is available for discussion. [ Ned Freed ] Send technical inquiries to service@innosoft.com. Product information, pricing, and literature can be obtained from sales@innosoft.com. The phone number is (909) 624-7907; FAX is (909) 621-5319. Street address is: Innosoft International, Inc. 250 W. First St., Suite 240 Claremont, CA 91711 4.3 Control Data Systems Mail*Hub package [ 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 rrr@svl.cdc.com 4.4 cc:MAIL support for MIME SMTPLINK 2.1 will support MIME. [ 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-Mail -- UNIX MUA [ Carlyn M. Lowery 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: (415) 499-8649 fax: (415) 479-0448 e-mail: info@z-code.com 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 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: +358 0 43577340 Fax: +358 0 43577348 Email: info@sti.fi 4.7 Frontier Technologies Super-TCP mail system [ Ray C Langford 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 TCP@FrontierTech.COM or call +1 414 241-4555. 4.8 PP -- UNIX MTA PP is a Mail Transport Agent (MTA), kindof son-of-MMDF-plus-X.400. It is built on ISODE. [ Harald Alvestrand 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 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.) 4.10 Eudora -- Macintosh MUA A commercial version with more features than the freely available one. Contact Steve Dorner for details. 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 embolden 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-02.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. There are also a number of implementations being developed in Europe (hopefully these will not suffer the same restrictions on export). PEM will (eventually) be integrated with MIME. See draft-ietf-pem-mime-02.txt for the latest work on this. 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 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 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.) When a message is returned to the user as being too large to deliver, one possible approach might be to fragment the message using the MIME Message/Partial mechanism, and resubmit it. Depending on the exact reason for the "too large" rejection, this may or may not be a good idea. For example, the limitation may reflect the recipient's disk quota, in which case the fragmented message will not be fully deliverable either. The possibility of fragmentation should, therefore, be left to the user's discretion (not performed automatically by the SMTP client). 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. 5.10 Where can I get some sample MIME messages? thumper.bellcore.com:pub/nsb/samples/* 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 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: services@eitech.com 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 "servicemail-help@eitech.com" 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 "services@eitech.com" with subject "listserv subscribe pact-kit your-real-name". 6.2.2 Metamail "mailserver" [ Nathaniel Borenstein 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 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. 6.4 World Wide Web [ Marc VanHeyningen 26-Jun-1993 ] There is more-than-experimental work underway in the Internet World Wide Web (WWW) community to use MIME as the mechanism for marking the contents of information exchanged via HyperText Transfer Protocol (HTTP); the specification of HTTP/1.0 dictates that both the request and the response are more or less MIME-compliant messages. There are implementations already doing this today. Support is also included for format negotiation (e.g. a server might have both a PostScript and a plaintext version of a paper and decide which to send based on what the client can accept, presentation preferences, size, and the like.) It's nearly as complicated as the "badness" mechanisms in TeX, and unrelated to (and, for its application, probably superior to) the multipart/alternative MIME type. There is an FAQ for WWW in comp.infosystems.www 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 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 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 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 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 world.std.com:dist/gnus-mime.el.shar (also in the contrib tree of metamail) [ Joe Ilacqua 24-Jun-1993 ] "gnus-mime.el" is an ELISP package that adds support for MIME to GNUS. This is the second release: I consider it very beta, and I'm sure there are bugs, but it does work. It provides support both to read and to post USENET articles in MIME format. It's scarcest feature is support for mutli-part multi-media ".signatures". 9.4 trn trn 3.0 has support for reading MIME articles with metamail, and creating them with mhn. 9.5 INN [ Christopher Davis 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, Ron Barak, Jason Beyer, Nathaniel Borenstein, Yehavi Bourvine, David Collier-Brown, Mark Crispin, Dave Curry, Christopher Davis, Paul Eggert, Ned Freed, Alec Henderson, Marc VanHeyningen, Ian Hoyle, Joe Ilacqua, Dave Lacey, Ray Langford, Carlyn Lowery, Stuart Lynne, Keith Moore, Rich Ragan, Luc Rooijakkers, Marshall Rose, Larry Salomon Jr, Susan Straub, Jerry Sweet, Rick Troth, 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 | tim@pipex.net or | Usenet will also be converted to OSI-based PIPEX Ltd | tim@unipalm.co.uk | services in the long term - B Plattner et al. -- Tim Goodwin | tim@pipex.net or | Usenet will also be converted to OSI-based PIPEX Ltd | tim@unipalm.co.uk | services in the long term - B Plattner et al.