| = Multipurpose Internet Mail Extensions |
| :navtitle: MIME |
| |
| == Overview |
| |
| The base format of an email message is xref:messages/imf.adoc[Internet Message Format"], |
| but most contemporary messages use a format called |
| https://en.wikipedia.org/wiki/MIME["Multipurpose Internet Mail Extensions"]. |
| MIME specifies how to extend a valid IMF message, dealing with character encodings, |
| various file formats, and many other odds and ends that make email what it is today. |
| |
| A user of email rarely has to be concerned with the MIME specifications. Usually the |
| communications system should take care of all the nitty gritty, and even then MIME |
| processing is usually at a very low level. For this reason, the blissfully simple |
| conception of a simple "email" is usually just fine from the perspective of a user |
| and even in most cases for a developer. |
| |
| |
| |
| |
| == Specifications |
| |
| Multipurpose Internet Mail Extensions, or just MIME, functions much like an extension |
| to IMF in order to: |
| |
| * Add different character sets for internationalization |
| * Allow for processing of media types other than plain text |
| |
| === RFC2045 |
| |
| https://tools.ietf.org/html/rfc2045[RFC2045] ("Multipurpose Internet Mail Extensions |
| Part One: Format of Internet Message Bodies") |
| describes the message body format of an email. It is part of a serious of MIME |
| specifications including <<RFC2046>>, <<RFC2047>>, <<RFC2048>>, and <<RFC2049>>. |
| This particular document in the series specifies the various headers that |
| are used to describe the structure of a MIME message. |
| |
| |
| |
| === RFC2046 |
| |
| https://tools.ietf.org/html/rfc2046[RFC2046] ("Multipurpose Internet Mail Extensions |
| Part Two: Media Types") describes the various MIME media types, such as |
| plain text, images, videos, etc. It is part of the serious of MIME specifications |
| that includes <<RFC2045>>, <<RFC2047>>, <<RFC2048>>, and <<RFC2049>>. |
| |
| |
| |
| |
| === RFC2047 |
| |
| https://tools.ietf.org/html/rfc2047[RFC2047] ("MIME Part Three: |
| Message Header Extensions for Non-ASCII Text") describes, as the |
| title indicates, header extensions for non-ASCII text. It is part |
| of the series of MIME specifications that includes |
| <<RFC2045>>, <<RFC2046>>, <<RFC2048>>, and <<RFC2049>>. |
| |
| |
| |
| |
| === RFC2048 |
| |
| https://tools.ietf.org/html/rfc2048[RFC2048] ("Multipurpose Internet Mail Extensions |
| Part Four: Registration Procedures") describes the procedure for registering a MIME |
| type. It is not directly relevant to James, but is part of the MIME series that includes |
| <<RFC2045>>, <<RFC2046>>, <<RFC2047>>, and <<RFC2049>>. |
| |
| This specification was obsoleted by https://tools.ietf.org/html/rfc4288[RFC4288] |
| (which itself was obsoleted by https://tools.ietf.org/html/rfc6838[RFC6838]) and |
| https://tools.ietf.org/html/rfc4289[RFC4289]. |
| |
| |
| |
| === RFC2049 |
| |
| https://tools.ietf.org/html/rfc2049[RFC2049] ("Multipurpose Internet Mail Extensions |
| Part Five: Conformance Criteria and Examples") mainly describes what portions of MIME |
| must be supported by a conformant MIME implementation. It is part of the series that includes |
| <<RFC2045>>, <<RFC2046>>, <<RFC2047>>, and <<RFC2049>>. |
| |
| |
| |
| == James Model |
| |
| While a general, non-technical description of MIME is useful for most users |
| and developers, it is not sufficient for building a complex system like James. Meanwhile, |
| the technical specifications are unfortunately very messy and overly-complex due to |
| their history and the context in which they were developed. To make dealing with |
| emails possible and practical, James has defined its own version of what it means |
| to be an email. |
| |
| (TODO need a reference, please!) |
