multipart - What do the numbers in a multi-part email mean? -

I'm looking at the source of multi-part message from thunderbird (in the hope of writing my own multi-part message From ++ / Javascript)

I was wondering what the follow-up means (only part of the text and part of the email part of the email) and how much do I calculate it for my own program I can -Party Email:

  This MIME format has a multi-part message ------ = _ NextParty_32252.1057009685.31.001 Content Re-Type: multipart / alternative; Limit = "---- = _ NextPart_32252.1057009685.31.002" Content-Description: Message in optional text and HTML forms ------ = _ NextPart_32252.1057009685.31.002  

(Like

I understand the rest of the message code part.

You see the boundaries in the limit deviation, this does not mean anything. (Although there is no implementor to stop trying to include some meaning ).

They should be unique and that is The contents should not be contained within, which they encapsulate.

From:

5.1 Multipart Media Type

In the case of multipart organizations, in which one or more separate set data is mixed in the same body, a "multipart" media type should appear in the header of the field unit, one or more body in the body There are parts of each, each over a limit As mentioned earlier, the part of each body is before the front of the border before the boundary is included in the boundary limit. clearing the boundary

General Syntax

Multipurpose entities require a parameter in the content-type field, the "border" threshold line then the content type header field, alternate linear white space From the boundary parameter values, two Hafen characters ("-", decimal value 45) are defined as one line, and an ending CRLF.

Note: Because the delimiter of the boundary should not be explained in body parts, a user agent should take care to select a unique range parameter value range of values Values ​​[may be] designed to generate delimiter as a result of an algorithm, the data already present about the data can be explained with a very low probability. ... Simple border delimiter line is something like "---", in which there is a limit capacitance boundary of "-----".