MIME Definition
MIME (Multipart Internet Message Extensions) defines a message format (a set of documents) represents a mechanism of sending different file types as one part or together with common mail messages. Multipart Internet Message Extensions has headers that are defined by RFC 822 and extensions to those header definitions. Multipart Internet Message Extensions follows all standard SMTP and RFC 822 mail rules. This type of messages can be used for transporting mail objects with various types of complexity via any mail transport system compliant with SMTP.
Multipart Internet Message Extensions format allows textual message bodies in character sets other than US-ASCII, Non-textual and Multi-part message bodies, Textual header information in character sets other than US-ASCII. It simplifies and rebuilds complex files by encoding a file and transporting it as a message body. Also files can be sent as a series of messages with component parts of the file.
Multipart Internet Message Extensions Headers:
- Multipart Internet Message Extensions-Version
- Content-Type
- Content-Disposition
- Content-Transfer-Encoding
A MIME-compliant user agent can decode the message presenting it to the reader or providing it to another application as a file. Non-compliant user agent can process a MIME message but not be able to decode it. Most user agents usually include courtesy text in messages to give users of non-MIME user agents an indication of the message content (text is inserted ahead of any MIME parts).
A multipart/mixed Multipart Internet Message Extensions message can be composed of different data types. Each body part is delineated by a boundary (usually a text string). Web servers insert the Multipart Internet Message Extensions header at the beginning of any web transmission. It provides clients to use this content type or media type header to select an appropriate application for the type of data the header indicates.