Multipurpose Internet Mail Extensions (MIME) has become the most
widely supported attachment
encoding standard for supporting multimedia formats.
the development of MIME, there had been a previous attempt to develop
a multi-media capability for ARPANET email,
but it was too complex and did not succeed.
The MIME standard was a success because it added multi-media extensions
to the existing email system without changing the infrastructure -- an important
feature for any addition to an operational service with a large installed base.
The original impetus behind the development of MIME was the need to
transmit "international" character sets in Internet mail,
beyond the standard ASCII character set, to support international alphabets
and symbols. Nathaniel Borenstein at Carnegie Mellon University led
the design of MIME to handle international character sets, and an intentional
side-effect of this design was the capability to extend the labeling
scheme to different types of content, including multimedia content.
The modern MIME encoding standard was first defined in paragraph 4.3 of RFC 989, updated by paragraph 220.127.116.11 of RFC 1421, and now includes elements like Internet links inline to the email message body. MIME encodes
a file into the following 64 alphanumeric characters:
If your email application gives you a choice of which encoding system to use for email attachments, the MIME standard is almost always the best selection. MIME allows a wide range of file types to be safely encoded and decoded, and is now recognized by almost all email applications.
Resources. Request For Comment's describing MIME are listed below:
- RFC 1341; MIME:
Mechanisms for Specifying and Describing
the Format of Internet Message Bodies;
N. Borenstein, N. Freed; June 1992. Updated by RFC 1521 and RFC 1590.
- RFC 2045;
Multipurpose Internet Mail Extensions Part One: Format of Internet
Message Bodies; N. Freed, N. Borenstein; November 1996.
- RFC 2046;
Multipurpose Internet Mail Extensions Part Two: Media Types; N.
Freed, N. Borenstein; November 1996.
- RFC 2047;
Multipurpose Internet Mail Extensions Part Three: Message Header
Extensions for Non-ASCII Text; K. Moore; November 1996.
- RFC 2048;
Multipurpose Internet Mail Extensions Part Four: Registration
Procedures; N. Freed, J. Klensin, J. Postel; November 1996.
- RFC 2049;
Multipurpose Internet Mail Extensions Part Five: Conformance
Criteria and Examples; N. Freed, N. Borenstein; November 1996.