MIME

MIME (Multipurpose Internet Mail Extensions) is an extension of Internet e-mail message format. Among other things, it defines a standard way to attach files to an email message.

The file type identification system used by MIME, MIME types, is also used by a number of other formats and protocols, such as HTTP.

Format
A MIME-compliant message is identified by the presence of a "MIME-Version" message header. The other headers used by MIME begin with "Content-". (This applies to the top level of an e-mail message. If MIME content is embedded in another format such as S/MIME, it may not require a MIME-Version header.)

Since MIME data is usually found as part of a message (as stored or transmitted by various means) rather than as a standalone file, it usually doesn't have a file extension. MIME headers or MIME-encoded messages saved for archiving or as example files might sometimes have a .mime extension.

Specifications

 * RFC 2045: MIME Part One: Format of Internet Message Bodies
 * RFC 2046: MIME Part Two: Media types
 * RFC 2047: MIME Part Three: Message Header Extensions for Non-ASCII Text
 * RFC 2049: MIME Part Five: Conformance Criteria and Examples
 * RFC 2183: The Content-Disposition Header Field
 * RFC 2231: MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations
 * RFC 2387: The MIME Multipart/Related Content-type
 * RFC 3676: The Text/Plain Format and DelSp Parameters
 * RFC 3798: Message Disposition Notification
 * RFC 4289: MIME Part Four: Registration Procedures
 * RFC 5147: URI Fragment Identifiers for the text/plain Media Type
 * RFC 6532: Internationalized Email Headers
 * RFC 6533: Internationalized Delivery Status and Disposition Notifications
 * RFC 6838: Media Type Specifications and Registration Procedures

Sample files

 * http://libxad.cvs.sourceforge.net/viewvc/libxad/testfiles/ASCII/mime/ → *.mime