Report: Document Exchange using Electronic Mail,

Onno Benschop, Curtin University, 1995

Note: This document was published in 1995 and appears here for historical purposes. Information contained in this document is likely out of date, incomplete and references information that may not exist at the URL specified. The report was commissioned by the Committee of Australian University Directors of Information Technology. The original document was lost and the text below is a recreation from various sources.

Committee of Australian University Directors of Information Technology

Document Exchange using Electronic Mail

Executive Summary

This report was created to address the issue of document exchange using Electronic Mail or Email. This report describes the processes required to transfer a document from sender to recipient and the translation that may occur after the transfer.

When a document is exchanged using Email, the document is encoded on the senders' machine, attached to an Email message and transferred to the recipient. The Email message is decoded and the attachment is saved on the recipient's machine. After translation, the document is available to the recipient.

Document -> Encode-> Transfer -> Decode -> Translate-> Document

The main problem experienced by Email users is the lack of an automatic process to detect and decode the attachment. The "MIME" standard has been developed to enable automatic detection of attachment encoding types. This report will recommend that MIME is adopted amongst CAUDIT members.

A secondary problem is the difficulty encountered when translating a document between different application file formats. This report will recommend that documents are transferred in their native file format and translation is undertaken at the recipient's end.

Many users may be familiar with translating documents from one application to another but most have trouble identifying the encoding standard used in a particular Email message. If the automatic decoding used in their Email package fails, users are at a loss to understand what has happened and how they can resolve it. Most of these problems could be solved by adequate training for users.

In summary the recommendations of this report are:

  • users are trained in the use of Email and attachments
  • the document is saved in the author's native format
  • each Email message contains a description of the attachment
  • MIME is used as the preferred attachment standard
  • one attachment is sent per Email message

Author's Note

This report could not have been completed without the assistance of the following people: Des Thornton, Ian Hill, Jo Winship, John Winship, Mark McInerney, Rob Phillips, Rod Kevill, Steve Maddocks, the Internet community and support people from around Australia.

A special note to Nick Jenkins who patiently explained the use of the English language.

Onno Benschop - December 1995

1.0 Introduction

This report was written to address the problems associated with the exchange of information using Electronic Mail (Email). The report deals with the mechanisms in use around the world for information exchange using Email, the compatibility of those mechanisms, problems encountered when using them, as well as future developments.

1.1 What is in this report?

This report describes the processes and procedures necessary for document transfer using Electronic Mail (Email) on the Internet. This report investigates the most effective way of exchanging a binary document between two people.

The scope of the report is limited to Email transfer only. The issue of verifying the accuracy of the exchange between word processors and spreadsheets by different vendors is too complex to be covered in the time set for this report.

The report covers the file formats in use for the various platforms and the encoding standards developed to overcome their respective idiosyncrasies with respect to the transfer of binary documents across the Internet.

The decoding stage of the transfer and methods for standardising the transfer and the automatic decoding of an attached document are described. The translation between various applications and platforms is addressed from the perspective of both sender and recipient.

Alternative delivery methodologies that the Internet offers are described.

Implementation issues, such as cost and training are addressed.

2.0 Document Transfer

The most common method of information exchange across the Internet is Electronic Mail or Email. A message containing unformatted text can be transmitted across all Email platforms. Simple messages can easily be sent from one person to another without any complicated formatting.

Email was designed specifically to send simple text messages, all other enhancements have been added onto the existing system. When more complicated information needs to be exchanged, for example a word processed document, spreadsheet, picture, sound, video, etc, the Email system needs to encode information. An Email message that contains such an encoded piece of information is said to contain an attachment or enclosure.

A document is attached to an Email message using an encoding scheme; the message, (including the attachment) is sent to the recipient and the attachment decoded on arrival.

The encoding and decoding schemes used are mostly platform dependent because of different internal storage methods for the various operating systems. Standards exist for the most common encoding schemes.

After a document is successfully transferred between systems the format of the document becomes an issue. If the applications used by sender and recipient are different, the document needs to be translated from one application format to the another. This report does not in any way describe the process of the actual transmission across the Internet.

In addition to Electronic Mail, developments on the Internet, such as FTP and the WWW offer an alternative transmission medium. (See section 2.5 for further discussion.)

2.1 Attaching a document to an Email message

When a document is attached to an Email message, a complex process comes into play. The mail program reads the document and encodes it. The result of attaching a document to the Email message is that the message contains the text that's being sent as well as a copy of the encoded document that's attached (referred to in this report as "the attachment").

The Email message containing the attachment is then sent to the recipient through a number of local and/or remote gateways. Finally it is received in by the recipient's mail system. The recipient's mail program then reads the Email message and attempts to decode the message. After decoding the attachment, the recipient should have an identical copy of the sender's document.

Below is an overview of the process.

fig 1: Overview of process

The process of attaching a document should be invisible to both sender and recipient. The encoding and decoding of attachments would not be a problem if everybody used the same Email package to send and receive mail.

2.2 File Formats

Although the actual transfer of documents across the Internet is mostly platform independent, the successful decoding of an attachment on the recipient's computer depends on the method used to encode the document. Encoding schemes have been developed to address specific issues related to the various platforms.

There are many more platforms connected to the Internet than the three documented below. Within Australian Universities however, the following three are the most prevalent.

2.2.1 Macintosh

Macintosh files contain a resource fork and a data fork. In the case of most document files, the resource fork is empty and the data fork contains the information that makes up the document.

The Macintosh resource fork is normally only used in application programs, where it contains the programming code, icons, etc.

However, some applications use both. (For example the Nisus word processor.)

In addition to the presence of the two different forks, every file on a Macintosh contains a Type and Creator mnemonic. This makes it possible for the operating system to work out what sort of file it is (a plain text document, an application, an Excel spreadsheet, etc.). Examples of the Type and Creator mnemonic are (MSWD-WDBN) for a Word 5.1a document and (XCEL-XLS4) for an Excel 4 spreadsheet.

Because the Macintosh is the only system that uses this file format, information is generally lost when files created on the Macintosh are used on other platforms.

2.2.2 IBM PC compatible

In the case of PC files, there is no difference between documents and applications in the way the data is stored. The file extension of a file does not mean different formatting; it just helps to identify the file type.

Extensions are informally used to describe the contents. Examples are ".doc" for Word documents, ".xls" for Excel spreadsheets. (More details are given in Appendix C .) Extensions are used as a naming convention only and have nothing to do with the actual physical format of the file.

2.2.3 Unix

Files stored on a Unix system contain similar information to that contained within IBM PC compatible machines.

The extensions used on a Unix system are just as standardised as those in use in the PC world. As with PC's, extensions are used as a naming convention only and have nothing to do with the actual physical format of the file.

2.3 Mail Attachments

The encoding and decoding schemes used are mostly platform dependent because of different internal storage methods for the various operating systems. Standards exist for the most common encoding schemes.

2.3.1 Encoding Mail

The limitations for the transmission of information across the Internet are mostly of historical origin.

Some links, gateways and Email systems on the Internet are only capable of faithfully relaying 7 bit data. This means that if an Email message containing an 8 bit byte was sent across the Internet without any precautions, the information could get lost, garbled or even disrupt the mail system.

A number of encoding standards are used to exchange information across the Internet. ASCII, UUENCODE, BINHEX and MIME are the most common.

2.3.1.1 ASCII

The characters used in a word processing document use a standard called ASCII (American Standard Code for Information Interchange, pronounced "as-ski"). An example is the letter "A" that has the byte value 65. Only the first 128 byte values, or 7 bits out of an 8 bit byte are used. The other 128 have different meanings on different systems. An example is the value 229. On the Macintosh it looks like this: "Ă‚". The same value on the PC looks like this: "â•Ł".

An advantage that ASCII has over all encoding schemes is that it is widely used across the Internet. All recipients can read the alpha-numeric text, but formatting information cannot easily be sent.

ASCII is used across all Email systems and is the basis of the vast majority of encoding standards across the Internet.

2.3.1.2 UUENCODE

UUENCODE (pronounced "you you encode") was created in the Unix environment. It encodes the 8 bit bytes in a document into 7 bit bytes. In the case of PC and Unix files, no information is lost. However, in the case of Macintosh files, the resource fork is lost, as well as the Type and Creator information.

There are some exceptions to this, where Email gateways preserve Macintosh resource and data forks as well as Type and Creator information, even where the attachment is UUENCODEd. An example of this type of mail handling is the QuickMail Internet gateway.

A document attached and send from a non-Macintosh platform can be successfully decoded by the Email program. The decoded document does not contain Type and Creator information and the Macintosh operating system cannot open the document. Some mail programs read the DOS file extension and allocate a Type and Creator accordingly. (For example, Eudora for the Macintosh will recognise Word and Excel document extensions.)

UUENCODE is supported by all Unix systems, a large number of PC Email programs and some Macintosh Email programs.

UUENCODE was developed by Unix programmers and has been adopted by others. It has never been made into a standard and several incompatible versions of UUENCODE exist.

2.3.1.3 BINHEX

The BINHEX (pronounced "bin heks") standard was specifically created for Macintosh computers. It retains both the data and resource forks, as well as the Type and Creator of a Macintosh file. A PC file can also be BINHEXed without loss of information.

BINHEX is supported by a large number of PC and Macintosh Email programs, but support in the UNIX area is limited.

BINHEX was developed by Apple Computer and has been adopted in the Apple Macintosh developer community. It has not been ratified as an international standard.

2.3.1.4 MIME[1]

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 multimedia Email among many different computer systems that use Internet mail standards.

The MIME standard defines Email messages containing the following parts:

  • character sets other than ASCII
  • enriched text (bold, italic, underscore, etc.)
  • images
  • sounds
  • other messages (reliably encapsulated)
  • tar files
  • PostScript
  • FTPable file pointers

MIME supports not only several pre-defined types of non-textual message content, such as uLaw audio, GIF image files, and PostScript programs, but also permits definition of custom types of message parts.

The ability to create Email messages with audio and other non-textual content has been available for some time, but usually as part of a vendor-specific solution. For example both Macintosh QuickMail and Sun Mailtool users each have the ability to exchange audio and video attachments. However, a Mailtool user cannot read a QuickMail video attachment or vice versa.

MIME was carefully designed to survive many of the most bizarre variations of mail transport protocols, some of which transform, modify and delete (parts of) the headers and bodies of Email messages.

A major problem with transferring attachments is that mail programs do not have a common standard for describing the beginning, the end, the document type and the encoding standard used. MIME solves this problem by defining standard header types describing Email message content-parts. A further description of decoding of Email messages is found in section 2.3.2.

A MIME Email message could contain a text part, a PostScript part and a Microsoft Word part. Each recipient would be able to extract the part that they could use. All other standards only provide a method to exchange one type of document. If one recipient of a message has access to an ASCII-terminal, but has a PostScript printer, they would be able to print the document in the original format. If only the text was important, they could read the text part.

An advantage of MIME is that it is an extensible encoding standard.

MIME is used across a wide range of platforms. It has been created as an extensible standard and has been ratified in various international standards by the Internet community. (See Appendix G for further references.)

2.3.2 Decoding Mail

Encoding standards assume that the recipient's mail program is capable of automatically decoding the information when it arrives in their mailbox.

Some mail packages can decode and save BINHEXed attachments automatically, others can decode and save both UUENCODEd and BINHEXed information.

Incompatibilities exist between mail programs in the method used to describe the attachment type and its encoding standard. An Email message contains a header and a body. The header describes where the message came from, what the subject is, etc. It also describes the content type of the message. There is no single standard to describe the content type. Mail programs need to make educated guesses at the encoding method used. Normally human intervention can point at the encoding standard used, but most mail packages do not allow the user to manually decode the message using a particular standard.

The recipient of an Email message that was not decoded successfully needs to extract, or save the contents of the mail attachment as a file on their machine and then use the appropriate program to decode the information. One example for Unix, Macintosh, PC platforms is Mpack.

If a document is BINHEXed on a PC and then decoded using a Macintosh, the decoded file will still be without either type and creator information or resource fork, since this did not exist at the time the document was encoded.

2.3.2.1 EMIL

Another approach to decoding Email attachments encoded with different standards is to use a system-wide decoding utility, such as Emil.

Emil, a program created by the Swedish University Network, is a Unix based solution that allows for translation of Email messages to and from many encoding standards. When installed it can operate as a command line tool, or it can become part of the mail-server's operation, ensuring that all messages sent from that host are encoded using a particular standard.

EMIL can be used as a tool to convert messages to and from any given standard.

It should be noted that developments on the World Wide Web are rapidly making this solution obsolete.

2.3.2.2 Compatibility Server[2]

The Clarity Compatibility server transparently intercepts Email messages being sent and transforms them as necessary to bridge incompatibilities in three areas:

  • Differences in Email systems used by sender and recipient;
  • Differences in operating systems and their file identification conventions (eg., file extensions on DOS and Windows, resource forks on Macintosh) between sender and recipient;
  • Differences in application software used to send and receive the files

Similar in function to Emil, this product is installed on a central Unix Email system and converts Email and attachments as it arrives.

Each user is set up with an address book entry containing their application details, such as Wordprocessor, Spreadsheet and Email package used. Based on the application suite available on the recipients machine, Compatibility Server will translate files from one format to another.

This product was released on November 20th, 1995 and has currently not been tested.

2.4 Translating Documents

After document is encoded, attached and sent across the Internet, it arrives on the recipient's computer, where it is detached and decoded. When this process is successfully completed, an identical copy of the authored document exists on the recipient's computer.

Following a successful transfer between systems the format of the document becomes an issue. If the applications used by sender and recipient are different, a document needs to be translated from one format to the other.

The following areas impact on the successful translation of a document:

  • Method of document preparation
  • Intermediate standards, such as RTF, SYLK and WKS
  • Compression

An example of document transfer is the use of packages like Microsoft Word 6 for Windows, which is able to save documents in Macintosh Word 5 format. Word 5 is unable to read documents of this type if they contain embedded objects like graphics or spreadsheet-tables.

This report ignores the actual document sent and assumes that the word processors and spreadsheet programs, used by both sender and recipient, are capable of reading multiple formats. For example, Microsoft Word is capable of reading WordPerfect files and vice versa.

Initial studies examined RTF for word processing and WKS and SYLK for spreadsheets as a means of standardising information exchange between packages. With the continual modification of the standards, it is very difficult for software manufacturers to reliably create software to translate RTF and WKS, therefore this is not a recommended solution. For example, Microsoft has updated the RTF solution several times and various software developers are unable to keep up with the changes. The WKS and SYLK formats do not cover extended features, such as buttons in spreadsheets, borders, document links, etc.

Another aspect of the translation of documents to an intermediate format is that neither author, nor reader has control over the translation process. At best the author will be able to read the intermediate format and compare visually the differences, at worst the conversion the author sees may not be the conversion the reader sees.

A better approach is to utilise a binary transfer of the author's document and let the reader choose to use a conversion tool, or to acquire the application that the author used.

2.4.1 Document Preparation

To enable the recipient to read the contents of a document prepared by another application other than the one used by the author, involves the successful translation of the document by the recipients application.

For example, the two most popular word processing packages, Microsoft Word and WordPerfect, available on both IBM and Macintosh platforms, are capable of reading each other's document formats.

All comments made about word processors in this section are applicable to documents saved by spreadsheet programs and other applications.

A document saved in a non-native format loses information, or may be subject to translation and interpretation errors. If for example a Microsoft Word document was sent to a user with WordPerfect, there are three alternatives:

Alternative 1:

Send a Microsoft Word document and let the WordPerfect user translate it.

The Author creates the document in Microsoft Word and sends a copy of the document to the WordPerfect user. The WordPerfect application needs to translate the document using translators available within WordPerfect.

The translation happens on the recipient's system.

This is by far the best option. It allows users to have access to the original document at the time of receipt. If the recipient's software is unable to read the document, they still have the option to purchase the software used by the sender to have full access to the content of the document.

Alternative 2:

Translate the Microsoft Word document to WordPerfect and send it.

The Author creates the document in Microsoft Word and saves a copy from within Word as a WordPerfect file. The WordPerfect user can read the document without translation.

The translation happens on the sender's system.

This method allows for the recipient to read the document in their own format, however, the WordPerfect document saved is not a WordPerfect document. It is a document created by Microsoft Word, attempting to convert its internal format to that used by WordPerfect.

The biggest disadvantage of this method is that the original document information is lost before the document is sent. There are also incompatibilities between Microsoft Word's implementation of WordPerfect files. This method also assumes that the sender has prior knowledge of the word processing application that the recipient uses.

Alternative 3:

Translate the Word document to an intermediate standard, send it and let the WordPerfect user translate it.

The Author creates the document in Microsoft Word and saves a copy in the intermediate standard from within Word (for example RTF). The recipient then reads the intermediate file and translates it into WordPerfect.

Two translations occur, one on the sender's and one on the recipient's system.

At first glance this method seems the best solution. Each application developer could read and write their documents in this intermediate standard and for most purposes it should be the best solution.

Finding an intermediate standard that supports all document features without loss of information is a large problem. Each translation, either to the intermediate standard, or from the intermediate standard may involve loss of document attributes.

As soon as a new version of an application appears, the standard will have to be revised. A further description of the intermediate standards, RTF, SYLK and WKS is found below in section 2.4.1.1.

An Internet development called HTML, described in section 2.5.2.2, addresses this problem from a different perspective.

2.4.1.1 Intermediate Standards for Translation

Few solutions exist to translate a document into an intermediate format to enable another application to read the content. For word processing, one standard is called RTF. For spreadsheets, two common standards are SYLK and WKS.

2.4.1.2 RTF

RTF, or Rich Text Format was designed by Microsoft as a solution to exchange information between the various versions of Microsoft Word. Other application developers have implemented the ability to save documents in this format.

RTF has seen numerous enhancements and version changes. It is not a standard, but rather a solution to a problem which Microsoft had transferring documents from one version of Word to another version.

The current version of RTF is 1.3 and it is available from:

ftp://ftp.primate.wisc.edu/pub/RTF/

The RTF solution is not a viable one as a recommendation for exchanging documents. It has never been ratified as a standard and can only be viewed as a Microsoft proprietary solution.

2.4.2.3 SYLK/WKS

From a historic perspective the available interchange formats for spreadsheets are: SYLK and WKS.

VisiCalc and Lotus 1-2-3, the world's first two spreadsheet programs, could exchange documents using these SYLK and WKS. Today's Microsoft Excel also has the ability to read and write these formats.

Functionality in the first generation of spreadsheet programs is far removed from current implementations. Graphs, Buttons, Borders, Links and other enhancements are not covered by these formats so they are no longer appropriate.

2.4.2 Compression

When transferring documents across a network, size of the document is relevant to some extent. Compression algorithms exist to reduce the size of the transmitted document.

Many users will compress their attachments using compression tools, such as PKZip, and StuffIt. These documents are transferred across the mail system as any attachment.

At the recipient's end a document needs to be decoded, decompressed and perhaps translated for a successful transfer of the document.

Compressing a document before attaching it to an Email message adds one layer of complexity to the attachment decoding.

2.5 Other Ways of Exchanging Information

Developments on the Internet allow for other means of exchanging documents electronically. The oldest standard is FTP, but developments since the 1991 introduction of the World Wide Web or WWW, have moved the Internet into a much friendlier environment to exchange information.

The basic difference between Email and the methods described below is that Email arrives on the recipients desktop without their intervention. The methods described below, FTP and WWW, ask that the recipient retrieves the message at their leisure.

The implications of these major difference are:

  • FTP and WWW are easy to ignore - Email is not.
  • Email security is based with the recipient - FTP and WWW security with the sender.

As a result, Memo's should be sent via Email, but reports can be distributed using FTP and WWW.

2.5.1 FTP

When a document is transferred using Electronic Mail, an encoded copy of the document is sent across the Internet to all recipients of the message. Another possibility is to make a copy of the document available without having to worry about the conversion in the Email package.

FTP, or File Transfer Protocol, allows for users to log into a remote machine and retrieve a document from that machine. The transfer should be made as a binary file and both parties, the author and the reader, will have an identical copy of the document.

Every reader needs to retrieve a copy of the document. If the author is sending a document to a mailing list, one person has to do the task of attaching and sending, once. Using FTP, every reader on the list will have to retrieve the document separately.

In addition, each recipient may have to be issued with a Username and Password to ensure the privacy of the document.

When making Macintosh documents available for FTP from a non-Macintosh platform, the document needs to be encoded to maintain the data and resource-fork integrity. There are two encoding schemes available to do this, BINHEX and MacBinary.

This method of exchanging information is much like when the postman leaves a note in a mailbox saying that there is a package to be collected at the post office. The recipient walks to the post office, where they receive the package.

2.5.2 The World Wide Web (WWW)

When a document is exchanged using either Email or FTP, the document ends up on the recipient's computer. An alternative is to only view a copy of the document, leaving the original located on a server at the Author's site. The Internet is ideal for this method of exchange.

An implementation of this publishing mechanism is called the World Wide Web or WWW.

The WWW is an Internet client-server Hypertext distributed information retrieval system which originated from the CERN High-Energy Physics laboratories in Geneva, Switzerland.[3]

On the WWW everything (documents, menus, indices) is represented to the user as a Hypertext object in HTML format. Hypertext links refer to other documents by their URLs. These can refer to local or remote resources accessible via FTP, Gopher, Telnet or News, as well as those available via the HTTP protocol used to transfer Hypertext documents.[3]

Client programs or browsers, such as Netscape, Mosaic or Lynx, run on the user's computer. They provide two basic navigation operations: to follow a link, or to send a query to a server.

Electronic Mail works with a method called "Store and Forward". If the recipients machine is not available at the time that a person is sending mail, the message gets stored and forwarded at a later time. However, FTP and the Web need to have direct connection at the time of retrieval. If either sender or recipient lives at the end of a telephone connection, these exchange methods might not be a solution.

2.5.2.1 URLs

If an Author chooses to distribute the information contained in their document using either FTP or the World Wide Web, the recipient will have to copy and paste the location information for the document into their web browser.

However with the continuing development of smarter and smarter software, a new trend seems to be developing. If a reader clicks on a URL (A Uniform Resource Locater: a method of describing the type of service, the location of the service and the location of the document on the service) in the middle of the document they are reading, the application will launch a Web browser and go to that location.

The latest beta version of Netscape, 2.0b2 includes a MIME compliant mail program. All URLs mentioned in Email stored with Netscape become click-able links.

This means that the major disadvantage of using the Web or FTP as a distribution method disappears. Since the reader will already have to click or select the attachment, there is no reason why that attachment could not still be on the author's machine - provided that Username and Password access has been given since most documents are not for public access.

It should be noted that MIME supports this type of attachment description in the form of FTP-able file pointers. (Although not many mail programs implement this feature.)

2.5.2.2 HTML

Applications create documents with contents. Each application stores the content in a proprietary internal format. Each internal format is different. Translation between formats is a problem. Solutions for intermediate formats are further described in section 2.4.1.1.

A different approach to the problem has been created with the advent of the World Wide Web and the language to describe documents on the WWW, called HTML, or Hyper-Text Markup Language. A document is described using a standard document description language, readable by numerous browsers. Documents on the WWW become containers for other documents of any electronic type imaginable.

A quick look at any given web server will show a text based document with links to other web documents, support for different character sets for different languages, embedded graphics, links to other services such as mail, News, FTP, Gopher, embedded sounds, video and so-on.

Currently there are few mail programs available that are able to read HTML documents. There are no word-processors available to author HTML documents. HTML can at the moment only easily be created in either a programming environment or as part of an automatic conversion process. Several applications exist to convert RTF (Rich-Text-Format) documents to HTML.

There are many examples of Web documents available. The Curtin Computing Centre has, for example, made its HowTo documentation, traditionally printed on paper, available on the Web. To access these documents, go to:

http://www.curtin.edu.au/curtin/dept/cc/docs/howto/

There are no conversion problems with images, sound and video, since the Web browser takes care of this. However, World Wide Web because documents are viewed using a browser, each reader will have a slightly different view of the same document. A browser is created for every type of machine, including some fledgling developments for hand held devices, such as the Apple Newton. The systems used are disparate. For example, the Newton does not have colour, a Unix text terminal does not have graphics.

Depending on the implementation of the browser, different views of the same document may not be a problem where the content is more important than how many words are viewed on a line.

3.0 Electronic Mail survey

All universities in Australia were asked a number of questions about Email on their campus. Below are the results of the survey.

Across the 25 organisations who responded, the following Email packages were in use:

      Number of sites              %             Number of Users         % user  
                               sites                                             
   1  Eudora                     76%          1  Elm                        26%  
   2  Elm                        44%          2  Eudora                     20%  
   3  Pegasus Mail               40%          3  Pegasus Mail               19%  
   4  Pine                       40%          4  Pine                       14%  
   5  VMS mail                   24%          5  VMS mail                   10%  
   6  Mailtool                   16%          6  Microsoft Mail              2%  
   7  Microsoft Mail             16%          7  mail/mailx                  1%  
   8  MH                         12%          8  cc:Mail                     1%  
   9  POPMail                    12%          9  MH                          1%  
  10  cc:Mail                     8%         10  POPMail                     1%  
  11  Quick Mail                  8%         11  WinQVT                      1%  
  12  WinQVT                      8%         12  Quick Mail                 <1%  
  13  ZMail                       8%         13  Mailtool                   <1%  
  14  mail/mailx                  4%         14  ZMail                      <1%  
  15  VersaTerm-Link              4%         15  VersaTerm-Link             <1%  
                                                                                 
      Other Mailer's             16%             Other Mailer's              3%  

The first four packages in either column are identical. This means that most sites have this and the majority of users use these Email packages. These four packages are MIME compliant. (It should be noted that most sites use multiple packages.)

When users were asked about the encoding/decoding method of their Email package:

                 %pkg   
UUENCODE         76%    
MIME             63%    
BINHEX           53%    

The following packages claim to be MIME compliant:

Software            Platform                                 
Elm                 Unix                                     
Pegasus mail        DOS, Windows, Macintosh                  
Eudora              Macintosh, Windows                       
Pine                Unix, VMS                                
cc:Mail             DOS, Windows, Macintosh                  
MH                  Unix                                     
Mailtool            Unix                                     
Zmail               Unix                                     

From the responses, we can also find out what percentage of users uses a PC users versus the number of users with terminal (emulation) access:

Personal Computer       45%     
Terminal Services       53%     

Totals:

   Number of Organisations:  25      
        Number of Packages:  15      
          Access to e-mail:  49%     
             Use of e-mail:  22%     

Although nearly half of the surveyed population has access to Email, only a quarter actually uses the facilities. (A survey within Curtin shows that the general response is: "I don't need Email for my work.") Education and Training will increase the number of Email users in this area.

See Appendix B for more details.

4.0 Implementation Issues

To move toward a MIME based mailing solution means to change the way things are done currently. The physical costs will be limited to the purchase of MIME compliant software and in most cases that will be free.

However, hidden costs of training and support will initially increase to then taper off and eventually decrease to a level below the one currently incurred.

4.1 Conversion

Below is a summary of the conversion that users would need to make. On the left is a column of current Email solutions and on the right the suggested migration to a MIME compliant Email solution.

Current solution    MIME based solution                                  
Mail/mailx          convert to Elm or Pine                               
Mac Pegasus mail    convert to Eudora                                    
Popmail             convert to Pegasus mail or Eudora                    
Versaterm-link      convert to Eudora                                    
VMS mail            convert to Pine                                      
Winqvt              convert to Pegasus mail or Eudora                    
Microsoft Mail      install EMIL, Compatibility Server or  MIME gateway  
QuickMail           install EMIL, Compatibility Server or  MIME gateway  
Elm                 upgrade to Elm with MIME extensions                  
Pine                upgrade to Pine with MIME extensions                 
cc:Mail             stay with cc:Mail                                    
Eudora              stay with Eudora                                     
Mailtool            stay with Mailtool                                   
MH                  stay with MH                                         
PC Pegasus mail     stay with PC Pegasus mail                            
Zmail               stay with Zmail                                      

Table 1. Email Package Conversion Process

4.2 Training

Finding software tools to resolve the problem of sending electronic documents across Email systems is only one part of the solution. At present most mail systems do their job adequately. There are still times when even the best software is confronted with a problem that it cannot solve without intervention from a human user.

If an inexperienced user with the correct tools and installation is confronted with an unexpected difficulty related to an attachment in an Email message, technical assistance to that user will be necessary.

As long as a user is made aware of the issues involved in getting a document from sender to receiver, a majority of the problems will disappear.

At Curtin the Computing Centre has been running a series of training seminars. Each seminar takes two hours and covers the basics of Electronic Mail use, the addressing, the concepts and attachments. A session is attended typically by 10 to 20 staff and post graduate students. There is no cost to attendee's, however budget needs to be allocated to cover trainers and facilities.

4.2.2 Support

Support for Email at present is mostly concerned with the decoding of messages and the translation. Questions about encoding standards have to be answered and central directory services need to be maintained.

The recommendations set out in this report reduce some support issues. Initially there will be increased load, but after training has been completed, decoding should become less of an issue. Encoding standards questions will reduce.

However, the translation issues will remain. The maintenance of central directory services will increase because of the increased use of Email.

4.3 Life Time of recommendations

The recommendations set out in this report are changing as new developments become available. A new SMTP server based solution called "Compatibility Server" was announced on November 20, 1995. It purports to decode, translate and re-code on the fly to specific user set up needs.

Email and its current use will evolve into a more integrated communications solution to allow central directory services, calendar with scheduling facilities and platform independent viewing of documents.

MIME is the only Email encoding standard that has been ratifies by the Internet community. It is extensible and used not only in Email transfers, but is widely used on the WWW. More and more MIME tools are becoming available and as such this standard will be used well into the next decade.

5.0 Recommendations

The recommendation for exchange of electronic documents through Email is to use MIME as the method of attaching documents to Email messages.

Users who are using personal computers to initiate terminal sessions on central Unix and VMS computers should use Eudora or Pegasus mail to POP mail off the central mail system. Users using QuickMail and Microsoft Mail will need to use EMIL until the Internet gateways for those products are MIME compliant.

Experiments show that there are problems with the Macintosh Pegasus Mail implementation of MIME and currently it is not recommended as a MIME compliant mail solution.

When sending an Email message, attach only one document to the message. This ensures that a manual decode will be much easier to complete if the recipients mail package is unable to decode the attachment.

In the body of the Email message describe the document and it's encoding scheme in such a way that the person receiving can manually decode and translate the document, if necessary. For example:

This message contains a Word 5.1a document that has been stuffed (.sit) and sent as a MIME attachment. It is formatted for use on a LaserWriter, with A4 paper.

This could be achieved by inserting a line in the signature at the end of the Email message like:

Documents attached to this Email are Macintosh Word 5.1a and Excel 5 formatted for A4 LaserWriters.

Appendix A Glossary of Terms

ASCII               American Standard Code for Information Exchange. The             
                    predominant character set encoding of present-day computers.     
                    The modern version uses 7 bits for each character, whereas       
                    most earlier codes (including an early version of ASCII) used    
                    fewer. This change allowed the inclusion of lower case -         
                    letters a major win - but it did not provide for accented        
                    letters or any other letter forms not used in English (such as   
                    the German sharp-S or the ae-ligature which is a letter in,      
                    for example, Norwegian)                                          

BINHEX              A Macintosh format for representing a file in text form. The     
                    file is converted to lines of letters, numbers and               
                    punctuation. Because BINHEX files are simply text they can be    
                    sent through most Electronic Mail systems and stored on most     
                    computers. However the conversion to text makes the file         
                    larger, so it takes longer to transmit a file in BINHEX format   
                    than if the file was represented some other way. The suffix      
                    ".hqx" usually indicates a BINHEX format file.                   

browser             A program which allows a person to read hyper-text. The          
                    browser gives some means of viewing the contents of nodes and    
                    of navigating from one node to another. Mosaic, Lynx and W3      
                    are browsers for the World-Wide Web. They act as clients to      
                    remote servers.                                                  

data fork           Part of a file on a Macintosh file system. A file consists of    
                    two parts, the data fork and the resource fork. The data fork    
                    contains any information that an application wishes to store.    
                    (Also see resource fork.)                                        

FAQ                 A document provided for many USENET newsgroups which attempts    
                    to answer Frequently Asked Questions which new readers often     
                    ask. These are maintained by volunteers and posted regularly     
                    to the news group.                                               

FTP                 File Transfer Protocol: A client-server file transfer protocol   
                    which allows a user on one computer to transfer files to and     
                    from another computer over a TCP/IP network. Also the client     
                    program the user executes to transfer files. It is defined in    
                    STD 9, RFC 959.                                                  

GIF                 Graphics Interchange Format, a standard for compressed           
                    digitised images, defined in 1987 by CompuServe.                 

GNU                 A recursive acronym: "GNU's Not Unix!". The Free Software        
                    Foundation's project to provide a freely distributable           
                    replacement for Unix. The GNU Manifesto was published in the     
                    March 1985 issue of Dr. Dobb's Journal but the GNU project       
                    started a year and a half earlier when Richard Stallman was      
                    trying to get funding to work on his freely distributable        
                    editor, Emacs.                                                   

Gopher              A popular distributed document retrieval system which started    
                    as a Campus Wide Information System at the University of         
                    Minnesota. Many hosts on the Internet now run Gopher servers     
                    which provide a menu of documents. A document may be a plain     
                    text file, sound, image, submenu or other Gopher object type.    
                    It may be stored on another host or may provide the ability to   
                    search through certain files for a given string. Gopher is       
                    defined in RFC 1432.                                             

helper application  A program that can deal with a specific data-type. Examples      
                    are programs that display GIF's, play sounds, show QuickTime     
                    movies, decode BINHEX, etc.                                      

host                The name of a computer on the Internet.                          

HTML                Hyper-Text Markup Language. Document format used by the          
                    World-Wide Web.                                                  

MIME                A standard for multi-part, multimedia Email messages on the      
                    Internet. MIME provides the ability to transfer non-textual      
                    data, such as graphics, audio and fax. It is defined in RFC      
                    1341. It is also used on the World-Wide Web. It uses mimencode   
                    to encode binary data into base 64 using a subset of ASCII.      

MIME part           A mail message sent using MIME contains segments. Each segment   
                    is called a part. Each part contains type, name and content. A   
                    MIME capable program can either deal with each part itself or    
                    alternatively launch a separate "helper-application" that can    
                    deal with a given part.                                          

News                Short for USENET News. A distributed bulletin board system       
                    supported mainly by Unix machines and the people who post and    
                    read articles thereon. Originally implemented in 1979 - 1980     
                    by Steve Bellovin, Jim Ellis, Tom Truscott, and Steve Daniel     
                    at Duke University, it has swiftly grown to become               
                    international in scope and is now probably the largest           
                    decentralised information utility in existence.                  

PostScript          PostScript is an interpreted, stack-based language (like         
                    FORTH). It was used as a page description language by the        
                    Apple LaserWriter, and now many laser printers and on-screen     
                    graphics systems. Its primary application is to describe the     
                    appearance of text, graphical shapes and sampled images on       
                    printed or displayed pages. The language was developed by        
                    Adobe.                                                           

resource fork       Part of a file on a Macintosh file system. A file consists of    
                    two parts, the data fork and the resource fork. The resource     
                    fork contains programming code and resources that are not        
                    directly part of the program. It was implemented to allow        
                    Macintosh software to be localised. A process that translates    
                    elements seen on the screen into different languages without     
                    having to recompile the source-code.                             

RFC                 Request for Comment. The internet community defines standards    
                    using a request for comment, which turns into a standard after   
                    due processing.                                                  

RTF                 Rich Text Format, an interchange format from Microsoft for       
                    exchange of documents between Word and other document            
                    preparation systems.                                             

sendmail            A Unix program that sends mail between hosts on the Internet.    

tar                 To create a transportable archive from a group of files by       
                    first appending them together with a Unix program called tar     
                    (the Tape ARchiver) and then compressing the result.             

Type and Creator    A description of file type and application that created the      
mnemonic            file on a Macintosh file system. It allows a document to be      
                    associated with its creating program.                            

uLaw                Computers (and audio compact discs and digital audio tape)       
                    handle sound by storing a sequence of discrete samples. The      
                    continuous sound waveform from the original source is sampled    
                    tens of thousands of times a second. Each sample represents      
                    the intensity of the sound pressure wave at that instant.        
                    Apart from the sampling frequency, the other parameter is the    
                    digital encoding of each sample including the number of bits     
                    used. The encoding may be linear, logarithmic or ulaw.           

URL                 Uniform Resource Locater, previously "Universal". A draft        
                    standard for specifying an object on the Internet, such as a     
                    file or news group. URLs are used extensively on the             
                    World-Wide Web. They are used in HTML documents to specify the   
                    target of a hyperlink.                                           

UUENCODE            Unix program for encoding binary data as ASCII. UUENCODE was     
                    originally used with UUCP (Unix to Unix copy) to transfer        
                    binary files over serial lines which did not preserve the top    
                    bit of characters but is now used for sending binary files by    
                    Email and posting to USENET newsgroups etc.                      

Web                 Short for World-Wide-Web, an Internet client-server hyper-text   
                    distributed information retrieval system originating from the    
                    CERN High-Energy Physics laboratories in Geneva, Switzerland.    
                    In WWW everything (documents, menus, indices) is represented     
                    to the user as a hyper-text (hyper-media) object in HTML         
                    format. Links between documents take the form of URLs. These     
                    can refer to local or remote resources accessible via several    
                    different network protocols apart from the basic http protocol   
                    used to transfer hyper-text documents.                           

Appendix B Survey

A survey of Email packages in use was conducted among the Universities. This followed on from the survey conducted by Mike Steel, Information Technology Manager of University of Western Sydney.

The survey asked people on the CAUDIT mailing list, the User-services list and the Curtin support list a number of questions about mail used in their organisation. There were responses covering 25 organisations. In those organisations, 15 different packages were used.

Questions were asked about the size of the organisation, the number of staff, students and post-graduate students. Respondents were asked how much of the population had access to Email and how many people actually used it.

Of the people working and/or studying in those organisations, 49% has access to Email and 22% actually use it regularly. Most responses expect a growing usage and greater access in the future.

The respondents were asked to supply information about each mail package used in their organisation, the capabilities of those packages and whether it could deal with text, UUENCODE, BINHEX, MIME and other attachment types.

The most frequently named application was Eudora (76% of organisations use it) which is available for both Macintosh and PC and comes in a Public Domain version and also in a Commercial version. The Public Domain version handles the BINHEX and MIME encoding schemes and apart from some user-interface enhancements the only addition to the commercial version is the handling of UUENCODEd attachments.

The package with the most users was Elm. It covers more than 26% of users, followed by Eudora (20%) and Pegasus Mail (19%). Elm is used on Unix machines and the latest versions are MIME compliant with helper applications, and can also handle UUENCODEd attachments. Elm is available in the Public Domain.

The other two most used and named applications were Pegasus Mail and PINE (14%). Pegasus Mail is available for DOS, Windows and Macintosh. PINE is available for Unix and VMS. Both support MIME and UUENCODE. In addition, Pegasus Mail supports BINHEX. Both are available in the Public Domain. Pegasus Mail's author sells the manual to cover development costs.

60% of total responses mentioned Elm, Pegasus Mail, Eudora and PINE and these were used by 80% of the population.

A large number of people using Email on Unix and VMS systems are not able to read Word or Excel documents. This means, that even if the attachment is successfully decoded, it's still unreadable for users of those systems.

45% of respondents were using a personal computer to read mail. 53% were using some kind of terminal based service on either Unix or VMS.

A trial was conducted in two stages.

The first stage incorporated extensive testing in the user-services area of the Curtin Computing Centre. Users moved to MIME compliant mail packages, including Macintosh and PC versions of Eudora, Mailtool, Elm and PINE.

The trial showed that compatibility between Word 5.1a for the Macintosh and Word 6 was an issue. MIME attachments were decoded with no problems.

In the second stage, a trial was conducted with a group of users from a number of organisations. (See Appendix D for details) Documents with different formats were attached to mail messages using the recommendations set out in this report. The files ranged in size from 10 Kb to 4.7 Mb. (See Appendix C for details)

The trial confirmed that the recommendation to use MIME was correct, given the constraints set out in this report. It also identified the following issues:

  • Pegasus Mail for the Macintosh claims to be MIME compliant, but currently only sends MIME messages. It is unable to decode the MIME attachment.
  • Single MIME users in a non-MIME environment have continual compatibility problems with mail packages which are not able to decode MIME attachments.
  • List servers will have to be configured to enable MIME headers. A message can be sent to members of the list that is not recognised as MIME by the mail programme.

The trial results reflect the complex nature of testing Email packages. Users had little problem once their mailer was configured for MIME use. A much larger aspect of the trial reflects associated issues, such as compatibility with printers and software. These issues fall outside the scope of this report.

Some side issues which were discovered during the trial were:

  • Results show that user training is an issue to address problems like:
    • "I received this PageMaker document, but I couldn't open it in Word."
    • Results show that if the mailer used is MIME compliant, the message came through in most cases. Some users showed that if the mail attachment was large, their mail platform had problems. This is more a set-up issue than one of compatibility.
  • The trial showed as a side effect that Microsoft Excel and Word were the more commonly used productivity tools and that WordPerfect was not used much in the trial sites.
  • The trial shows that users with terminals, rather than Macintosh or PC, were unable to use the documents, even though their mail package successfully decoded the attachment, some users commented on this.

The mailer I use is capable of:

                  Yes   No     
UUENCODE          76%   22%    
MIME              63%   34%    
BINHEX            53%   44%    

Totals:

Number of               25      
Organisations                   
Number of Packages      15      
Access to Email         49%     
Use of Email            22%     

PC users versus terminal users:[4]

Personal Computer          45%  
Terminal services          53%  

Number of sites that use:

Eudora                      19  76%     
Elm                         11  44%     
Pegasus Mail                10  40%     
Pine                        10  40%     
VMS mail                     6  24%     
Mailtool                     4  16%     
Microsoft Mail               4  16%     
MH                           3  12%     
POPMail                      3  12%     
cc:Mail                      2  8%      
Quick Mail                   2  8%      
WinQVT                       2  8%      
ZMail                        2  8%      
mail/mailx                   1  4%      
VersaTerm-Link               1  4%      
                                        
Other Mailer's               4  16%     

Number of users per package:

Elm                      17532  26.13%  
Eudora                   13686  20.39%  
Pegasus Mail             13018  19.40%  
Pine                      9233  13.76%  
VMS mail                  6670  9.94%   
Microsoft Mail            1142  1.70%   
mail/mailx                 950  1.42%   
cc:Mail                    840  1.25%   
MH                         750  1.12%   
POPMail                    550  0.82%   
WinQVT                     450  0.67%   
Quick Mail                 290  0.43%   
Mailtool                   258  0.38%   
ZMail                       40  0.06%   
VersaTerm-Link               5  0.01%   
                                        
Other Mailer's            1692  2.52%   

Below is the survey form that was sent out to all Australian Universities using the CAUDIT Email list.

Organisation: 
Type of Organisation: 
Number of Staff: 
Number of Students: 
Number of Postgraduate Students:
Number of people with access to Electronic Mail: 
Number of people actually using Electronic Mail:
Email Package: 
Version used: 
In the Public Domain: 
Author: 
Platform(s) used: 
Number of users who use this package across all platforms:
Attachments that the package supports are 
Send text: 
Send BINHEX: 
Send UUENCODE: 
Send MIME: 
MIME-types sent: 
Send Other (name them): 
Receive text: 
Receive BINHEX: 
Receive UUENCODE: 
Receive MIME: 
MIME-types received: 
Receive Other (name them):
Formats that the package supports are 
Send Sound: 
Send Video: 
Send Graphics: 
Send Attachments: 
Receive Sound: 
Receive Video: 
Receive Graphics: 
Receive Attachments: 
Comments about this package:

Appendix C Document details

The list below contains the document details that were used to trial MIME as a transport mechanism. The documents were sent to participants using the platform indicated.

File Name    Format                    Pages  Size     Platform Sent from    
btw7.pm5     PageMaker 5 for               4  4,983,7  Macintosh Eudora      
             Macintosh                             90  v1.5.1                
calc.xls     Excel 4 for Macintosh         2   68,434  PC Eudora v1.4.4      
chart.xls    Excel 4 for Macintosh         1   12,637  Elm v2.4 PL24         
example.wp5  WordPerfect 5.2 for           1   32,944  PC Pegasus Mail       
             Windows                                   v1.2.1                
example.wp6  WordPerfect 6 for             1   55,385  Pine v3.91-VMS        
             Windows                                                         
struct.wp6   WordPerfect 5.2 for           4    9,379  Macintosh Eudora      
             Windows                                   v1.5.1                
struct.wp6   WordPerfect 6 for             4   19,366  Elm v2.4 PL24         
             Windows                                                         
waterm.wp6   WordPerfect 6 for             1   45,551  Pine v3.91            
             Windows                                                         
word2.doc    Word 2 for Windows           20  4,577,2  Macintosh PMail       
                                                   80  v2.1.2                
word6.doc    Word 6 for Windows           20  4,616,1  Pine v3.91            
                                                   92                        

Appendix D Sites

Below is a list of the participants in the project.

Participants in the Email survey.    Participants in the Electronic          
                                     Document Transfer Trial.                
Antarctic Division                   Curtin University of Technology         
Australian Defence Force Academy     Deakin University                       
Australian National University       James Cook University                   
Australian Vice-Chancellors          La Trobe University - Bendigo           
Committee                                                                    
Curtin University of Technology      Macquarie University                    
Deakin University                    Murdoch University                      
Edith Cowan University               Northern Territory University           
Griffith University                  Royal Melbourne Institute of            
                                     Technology                              
James Cook University                The University of Adelaide              
La Trobe University - Bendigo        University of South Australia           
Lincoln University                   University of Western Sydney            
Macquarie University                                                         
Massey University                                                            
Murdoch University                                                           
Northern Territory University                                                
Queensland University of Technology                                          
Royal Melbourne Institute of                                                 
Technology                                                                   
The University of Adelaide                                                   
The University of Sydney                                                     
University of New South Wales                                                
University of Otago                                                          
University of South Australia                                                
University of Southern Queensland                                            
University of Western Sydney                                                 
Victoria University of Wellington                                            

Appendix E Packages

Appendix E: Inventory of Email software

Package:            cc:Mail                                     
Upgrade path:       Upgrade to the current version.             
Current Version:    Mac: 2.1.1 PC: 4.02 Win: 2.10               
Author:             Lotus, Innosoft                             
Availability:       Commercial                                  
cc:Mail supports the following attachment methods:                 
         UUENCODE:  Only as a MIME part                         
           BINHEX:  None                                        
             MIME:  Yes, supports: text/plain, text/rtf,        
                    application/octet-stream                    

Out of 25 organisations, 8% use cc:Mail. The number of cc:Mail users across all organisations is 1% of the total user community.

User comments:

Had no problems sending MIMEd attachments to organisations using MIME.

It is limiting in terms of formatting messages.

The [mail] database is in a single file and is easily corrupted with local pc and system crashes.

Package:            Elm                                         
Upgrade path:       Upgrade to the current version.             
Current Version:    Unix: 2.4 PL24 PC: 2.3                      
Author:             Usenet Community Trust                      
Availability:       Believed to be in the Public Domain.        
Elm supports the following attachment methods:                     
         UUENCODE:  Yes                                         
           BINHEX:  Only with helper applications               
             MIME:  Yes if MIME version is installed            

Out of 25 organisations, 44% use Elm. The number of Elm users across all organisations is 26% of the total user community.

User comments:

Not graphical, used as a simple Email package.

Runs well, needs large spooling area

Package:            Eudora                                      
Upgrade path:       Upgrade to the current version.             
Current Version:    Mac: 1.5.1  2.1.1 Commercial Win: 1.4.4     
                    2.0 Commercial                              
Author:             Qualcomm                                    
Availability:       Version 2.x is commercially available.      
Eudora supports the following attachment methods:                  
         UUENCODE:  Only supported by the commercial version.   
           BINHEX:  Yes                                         
             MIME:  Yes, supports: BINHEX, Base64               

Out of 25 organisations, 76% use Eudora. The number of Eudora users across all organisations is 20% of the total user community.

User comments:

Excellent interface and set up capabilities. Looks the same on Windows & Mac, user configurable, handles SLIP easily.

Package:            Mail/mailx                                  
Upgrade path:       Convert to Elm or Pine.                     
Current Version:    Unix: 5.0                                   
Author:             Berkley                                     
Availability:       Believed to be in the Public Domain.        
Mail/mailx supports the following attachment methods:              
         UUENCODE:  Yes                                         
           BINHEX:  Yes                                         
             MIME:  None                                        

Out of 25 organisations, 4% use Mail/mailx. The number of Mail/mailx users across all organisations is 1% of the total user community.

Package:            Mailtool                                    
Upgrade path:       Upgrade to the current version.             
Current Version:    Unix: 3.3                                   
Author:             Sun                                         
Availability:       Believed to be in the Public Domain.        
Mailtool supports the following attachment methods:                
         UUENCODE:  Yes                                         
           BINHEX:  Only with helper applications               
             MIME:  Yes                                         

Out of 25 organisations, 16% use Mailtool. The number of Mailtool users across all organisations is less than 1% of the total user community.

Package:            MH                                          
Upgrade path:       Upgrade to the current version.             
Current Version:    Unix: 6.8                                   
Author:             UCI                                         
Availability:       Believed to be in the Public Domain.        
MH supports the following attachment methods:                      
         UUENCODE:  Only with helper applications               
           BINHEX:  Only with helper applications               
             MIME:  Yes, simple to define new types             

Out of 25 organisations, 12% use MH. The number of MH users across all organisations is 1% of the total user community.

Package:            Microsoft Mail                              
Upgrade path:       An example of a MIME gateway is:            
                    http://www.ep.se/ep/eng/mimetic/mimetic.htm                                           
Current Version:    Mac: 3.1 Win: 3.2a                          
Author:             Microsoft                                   
Availability:       Commercial                                  
Microsoft Mail supports the following attachment methods:          
         UUENCODE:  Yes, if using the SMTP gateway. Uses        
                    internal file format for exchange within    
                    a Microsoft Mail network.                   
           BINHEX:  No                                          
             MIME:  No                                          

Out of 25 organisations, 16% use Microsoft Mail. The number of Microsoft Mail users across all organisations is 2% of the total user community.

User comments:

Good front end, slow in peak periods, needs more than adequate resources to run well.

Package:            Pegasus Mail                                
Upgrade path:       Upgrade to the current version.             
Current Version:    Mac: 2.1.2 PC: 3.22 Win: 1.21               
Author:             David Harris                                
Availability:       Public Domain. Manuals are available for    
                    purchase.                                   
Pegasus Mail supports the following attachment methods:            
         UUENCODE:  Yes                                         
           BINHEX:  Yes                                         
             MIME:  The Macintosh version can send MIME mail,   
                    not receive it.[5] The PC version,            
                    supports: UUENCODE, BINHEX, Base64, GIF,    
                    JPEG, MPEG, Audio (AU), PostScript          

Out of 25 organisations, 40% use Pegasus Mail. The number of Pegasus Mail users across all organisations is 19% of the total user community.

User comments:

Viewing of MIME graphics/video/sound is not done natively by the program. Each site must set up external programs to view - Pegasus Mail merely identifies the MIME type and passes the attachment to the external program you associate with the MIME type.

Package:            Pine                                        
Upgrade path:       Upgrade to the current version.             
Current Version:    Unix:  3.91 VMS: 3.89                       
Author:             University of Washington                    
Availability:       Believed to be in the Public Domain.        
Pine supports the following attachment methods:                    
         UUENCODE:  Yes                                         
           BINHEX:  None                                        
             MIME:  Yes                                         

Out of 25 organisations, 40% use Pine. The number of Pine users across all organisations is 14% of the total user community.

User comments:

This package is identical from a user's perspective under VMS and Unix. Set up is automatic.

Package:            Popmail                                     
Upgrade path:       Convert to Pegasus Mail or Eudora.          
Current Version:    PC: 3.2.2 PC: Beta version 3.2.3            
                    (Supplanted by "Minuet")                    
Author:             University of Minnesota                     
Availability:       Current versions are in beta development.   
Popmail supports the following attachment methods:                 
         UUENCODE:  Yes                                         
           BINHEX:  Yes                                         
             MIME:  No                                          

Out of 25 organisations, 12% use Popmail. The number of Popmail users across all organisations is 1% of the total user community.

User comments:

The University of Minnesota is not developing this software any further. Currently there is a beta version of Minuet available. Minuet has the same functionality as Popmail with mail support but includes Gopher, News, Telnet, FTP and Finger support.

Package:            QuickMail                                   
Upgrade path:       Install EMIL to convert messages to and     
                    from MIME.                                  
Current Version:    Mac: 3.0 Win: 3.0                           
Author:             CE Software                                 
Availability:       Commercial                                  
QuickMail supports the following attachment methods:               
         UUENCODE:  Yes                                         
           BINHEX:  None                                        
             MIME:  None                                        

Out of 25 organisations, 8% use QuickMail. The number of QuickMail users across all organisations is less than 1% of the total user community.

User comments:

Internet Gateways for this package are not robust and expensive.

Package:            Versaterm-link                              
Upgrade path:       Convert to Eudora.                          
Current Version:    Mac: 1.1.1                                  
Author:             Ablebeck Software                           
Availability:       Commercial                                  
Versaterm-link supports the following attachment methods:          
         UUENCODE:  None                                        
           BINHEX:  Yes, with StuffIt Compression if chosen.    
             MIME:  None                                        

Out of 25 organisations, 4% use Versaterm-link. The number of Versaterm-link users across all organisations is less than 1% of the total user community.

User comments:

Integrated mail, news, FTP, directory etc. Reasonable remote access, average GUI.

Package:            VMS mail                                    
Upgrade path:       Convert to Pine.                            
Current Version:    VMS: 6.1                                    
Author:             Digital Corp.                               
Availability:       Comes with VMS 6.1.                         
VMS mail supports the following attachment methods:                
         UUENCODE:  Only with helper applications               
           BINHEX:  Only with helper applications               
             MIME:  None                                        

Out of 25 organisations, 24% use VMS mail. The number of VMS mail users across all organisations is 10% of the total user community.

Package:            Winqvt                                      
Upgrade path:       Convert to Pegasus Mail or Eudora.          
Current Version:    Win: 3.9.8                                  
Author:             QPC Software                                
Availability:       Shareware                                   
Winqvt supports the following attachment methods:                  
         UUENCODE:  Yes                                         
           BINHEX:  No                                          
             MIME:  No                                          

Out of 25 organisations, 8% use Winqvt. The number of Winqvt users across all organisations is 1% of the total user community.

Package:            Zmail                                       
Upgrade path:       Upgrade to the current version.             
Current Version:    Unix: 2.1                                   
Author:             Z-Code Software Corp.                       
Availability:       Commercial                                  
Zmail supports the following attachment methods:                   
         UUENCODE:  Yes                                         
           BINHEX:  No                                          
             MIME:  Yes                                         

Out of 25 organisations, 8% use Zmail. The number of Zmail users across all organisations is less than 1% of the total user community.

Appendix F DOS file extensions

.123            Lotus Spreadsheet                         
.arc            File compressed using Arc                 
.bat            Batch file with DOS commands              
.com            Application                               
.dbf            dBase database file                       
.dbt            dBase memo fields file                    
.dic            Microsoft Dictionary file                 
.dll            Dynamic Link Library                      
.doc            Microsoft Word document                   
.dot            Microsoft Word Template file              
.drv            Driver file                               
.exe            Application                               
.gif            Graphic Interchange Format file           
.hlp            Help file                                 
.hqx            File encoded using BINHEX                 
.idx            dBase index file                          
.inf            Set up information file                   
.ini            Program initialisation file               
.jpg            JPEG encoded file                         
.lzh            File compressed using LHA                 
.mov            Video file                                
.mpg            MPEG encoded video file                   
.pif            Program Information file                  
.sys            Driver information file                   
.txt            Text file                                 
.wav            Sound file                                
.wri            Windows Write file                        
.xls            Microsoft Excel spreadsheet               
.zip            File compressed using PKZip / GZip        

Appendix G Related Documents

Information Exchange Steering Committee, Electronic Mail - Issues for Government Business, Canberra, February 1994

Internet Community, MIME FAQ, Internet, 26 February 1995,

http://www.cis.ohio-state.edu/text/faq/usenet/mail/mime-faq/top.html


RFC 1767; D. Crocker

MIME Encapsulation of EDI Objects


RFC 1741; P. Faltstrom, D. Crocker, E. Fair

MIME Content Type for BinHex Encoded Files


RFC 1740; P. Faltstrom, D. Crocker, E. Fair

MIME Encapsulation of Macintosh files - MacMIME


RFC 1652; J. Klensin, N. Freed, M. Rose, E. Stefferud, D. Crocker

SMTP Service Extension for 8bit-MIMEtransport


RFC 1641; D. Goldsmith, M. Davis

Using Unicode with MIME


RFC 1563; N. Borenstein

The text/enriched MIME Content-type


RFC 1556; H. Nussbacher

Handling of Bi-directional Texts in MIME


RFC 1522; K. Moore

MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text


RFC 1521; N. Borenstein, N. Freed

MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies


RFC 1496; H. Alvestrand, J. Romaguera, K. Jordan

Rules for downgrading messages from X.400/88 to X.400/84 when MIME content-types are present in the messages


RFC 1437; N. Borenstein, M. Linimon

The Extension of MIME Content-Types to a New Medium


RFC 1428; G. Vaudreuil

Transition of Internet Mail from Just-Send-8 to 8Bit-SMTP/MIME


RFC 1344; N. Borenstein

Implications of MIME for Internet Mail Gateways


The following documents have been superseded, but have been included for reference:


RFC 1523; N. Borenstein

The text/enriched MIME Content-type

(Obsolete)


RFC 1426; J. Klensin, N. Freed, M. Rose, E. Stefferud, D. Crocker

SMTP Service Extension for 8bit-MIMEtransport

(Obsolete)


RFC 1341; N. Borenstein, N. Freed

MIME (Multipurpose Internet Mail Extensions): Mechanisms for Specifying and Describing the Format of Internet Message Bodies

(Obsolete)

Appendix H Web References:

(As of noon, December 4th, 1995)

MIME FAQ:

http://www.cis.ohio-state.edu/text/faq/usenet/mail/mime-faq/top.html

Example of documentation on the Web:

http://www.curtin.edu.au/curtin/dept/cc/docs/howto/

Documentation for MIME compliant Microsoft Mail Gateway:

http://www.ep.se/ep/eng/mimetic/mimetic.htm

Documentation of the RTF standard:

ftp://ftp.primate.wisc.edu/pub/RTF/

Compatibility Server:

http://www.clarity.com