MIME - Multipurpose Internet Mail Extensions

Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of e-mail to support:

• Text in character sets other than ASCII
• Non-text attachments
• Message bodies with multiple parts
• Header information in non-ASCII character sets

MIME's use, however, has grown beyond describing the content of e-mail to describe content type in general, including for the web.

Virtually all human-written Internet e-mail and a fairly large proportion of automated e-mail is transmitted via SMTP in MIME format. Internet e-mail is so closely associated with the SMTP and MIME standards that it is sometimes called SMTP/MIME e-mail.

The content types defined by MIME standards are also of importance outside of e-mail, such as in protocls like HTTP. HTTP requires that data be transmitted in the context of e-mail-like messages, although the data most often is not actually e-mail.

MIME is specified in six linked RFC's: RFC 2045, RFC 2046, RFC 2047, RFC 4288, RFC 4289 and RFC 2049, which together define the specifications.