 message/RFC822 Alternative Parts are different versions of the same message RFC822 Body is an encapsulated message Message Partial Body is a fragment of a bigger message External body Body is a reference to another message Video Video is in MPEG format Audio Basic Single channel encoding of voice at 8KHZ Image is in JPEG format Image Image is in GIF format PostScript Adobe PostScript Application Octect stream General binary data of 8-bit bytes Figure 29.5 Content-Type => Type and subtype used in MIME. Fundamentals of EMS, NMS and OSS/BSS Content-Transfer-Encoding => The methods to encode the messages into zeros and ones to facilitate transport are defined by this header. Context-Transfer-Encoding: < type > The encoding can be: 7-bit: This encoding handles ASCII characters and short lines. It is a 7-bit ASCII encoding where the line length should not exceed 1000 characters. 8-bit: This encoding handles non-ASCII characters and short lines. It is an 8-bit encoding and sends non-ASCII characters but the line length should not exceed 1000. Binary: This encoding handles non-ASCII characters of unlimited length. It is an 8-bit encoding where non-ASCII characters can be sent and the line length can exceed 1000 characters. Base64: In this encoding, 6-bit blocks of data are encoded into 8-bit ASCII characters. It transforms the data made of bytes into printable characters that can be sent as ASCII characters or any character set type that is supported by the underlying mail transfer mechanism. Base 64 Alphabet Table Value Code Value Code Value Code Value Code Value Code Value Code Quoted-Printable: This encoding is used when the data consist mainly of ASCII characters with a small portion of non-ASCII characters. The ASCII characters are sent as it is, but the non-ASCII characters are sent as three characters-the first character being an equal sign (=), the second and the third are the hexadecimal representation of the byte. Content-Id => The whole message is identified in a multiple message environ- ment through the Con