Through the use of the multipart type, MIME allows messages to have parts red jordans arranged in a tree structure where the leaf nodes are any non-multipart content type and the non-leaf nodes are any of a variety of multipart types. This mechanism supports:

* simple text messages using text/plain (the default value for "Content-type:")
* text plus attachments (multipart/mixed with a text/plain part and other non-text parts). A MIME message including an attached file generally indicates the file's original name with the "Content-disposition:" header, so the type of file is indicated both by the MIME content-type and the (usually OS-specific) filename extension
* reply with original attached (multipart/mixed air retro shoes with a text/plain part and the original message as a message/rfc822 part)
* alternative content, such as a message sent in both plain text and another format such as HTML (multipart/alternative with the same content in text/plain and text/html forms)
* image, audio, video and application (for example, image/jpg, audio/mp3, video/mp4, and application/msword and so on)
* many other message constructs

[edit] Content-Disposition

The original MIME specifications only provided a means to jordans for sale associate filenames with application/octet-stream parts. This was done through the use of a name= parameter on the content-type. The theory here was that filenames were mostly used for type information and therefore did not need to be present in most cases. It was a mistake. The specification of content-disposition attempted to provide a more general means air retro shoes of providing file name information by defining a filename parameter as part of the content-disposition field.[2]

The following example is taken from RFC 2183, where the header is defined

Content-Disposition: attachment; filename=genome.jpeg;
modification-date="Wed, 12 Feb 1997 16:29:51 -0500";

The filename may be encoded as defined fake jordans by RFC 2231. Besides attachment, one can specify inline, or any other disposition type. Unfortunately, no name is defined for the nominal "default" disposition that air retro shoes corresponds to no content-disposition being present. Thus the recommended practice for generating agents is to only include filename information when it is necessary, also to avoid leaking sensitive information. If filename information has to be included, an agent should either put it in a filename= parameter or both a filename= and name= parameter. Never ever use just a name= parameter because that opens up to gratuitous interpretation men's jordans of the part using an unintended disposition value.[2]

[edit] Content-Transfer-Encoding

In June 1992, MIME (RFC 1341, cheap jordans since obsoleted by RFC 2045) defined a set of methods for representing binary data in ASCII text format. The content-transfer-encoding: MIME header has 2-sided significance:

1. It indicates whether or not a binary-to-text encoding scheme has been used on top of the original encoding as specified within the Content-jordan shoes Type header, and
2. If such a binary-to-text encoding method has been used it states which one.

The RFC and the IANA's list of transfer encodings define the values michael shoes shown below, which are not case sensitive. Note that '7bit', '8bit', and 'binary' mean that no binary-to-text encoding on top of the original encoding was used. In these cases, the header is actually redundant for the email client to decode the message body, but it may still be useful as an indicator of what type of object is being sent. Values 'quoted-printable' and 'base64' tell the email client that a binary-to-text jordans shoes encoding scheme was used and that appropriate initial decoding is necessary before the message can be read with its original encoding (e.g. UTF-8).

* Suitable for use with normal SMTP:
o 7bit – up to 998 octets per line of the code range 1..127 with CR and LF (codes 13 and 10 respectively) only allowed to appear as part of a CRLF line ending. This is the default value.
o quoted-printable – used to encode arbitrary octet sequencesair jordans into a form that satisfies the rules of 7bit. Designed to be efficient and mostly human readable when used for text data consisting primarily of US-ASCII characters but also containing a small proportion of bytes with values outside that range.
o base64 – used to encode arbitrary octet sequences into a form that satisfies the rules of 7bit. Designed to be efficient for non-text 8 bit data. Sometimes used for text data that frequently uses non-US-ASCII characters.
* Suitable for use with SMTP servers that support the 8BITMIME SMTP extension:
o 8bit – up to 998 octets per line with CR and LF retro jordans (codes 13 and 10 respectively) only allowed to appear as part of a CRLF line ending.
* Suitable only for use with SMTP servers that support the BINARYMIME SMTP extension (RFC 3030):
o binary – any sequence of octets.

There is no encoding defined which is explicitly designed for sending arbitrary jordan air shoes binary data through SMTP transports with the 8BITMIME extension. Thus base64 or quoted-printable (with their associated inefficiency) must sometimes still be used. This restriction does not apply to other uses of MIME such hijordan as Web Services with MIME attachments or MTOM