The ContentType property returns the MIME type for the
currently selected message part. The type string consists of a primary
type and secondary sub-type separated by a slash, followed by one or
more optional parameters delimited by semi-colons. For example, this
is a common content type for text messages:
text/plain; charset=utf-8
The text designation indicates that this message part
contains readable text, and the plain sub-type indicates that
the text does not contain any special encoding. The optional
parameter which follows the content type provides additional
information about the content. In this example, it specifies which
character set should be used to display the text. The two common
character sets used are UTF-8 and US-ASCII.
There are seven predefined, standard content types, each with
their own sub-types. The following table lists these types, along
with some common sub-types that are found in messages:
| Type |
Sub-Types |
Description |
| text |
plain, richtext, html |
Indicates that the message part contains text. This is the
most common type found in mail messages; if no content type is
explicitly defined, then it is assumed to be plain text |
| image |
gif, jpeg |
Indicates that the message part contains a graphics
image |
| audio |
basic, aiff, wav |
Indicates that the message part contains audio data; the
basic sub-type is 8-bit PCM encoded audio (commonly found with
the .au filename extension) |
| video |
mpeg, avi |
Indicates that the message part contains a video clip in the
specified format |
| application |
octet-stream, postscript |
Indicates that the message part contains application specific
data, typically used with the octet-stream sub-type to indicate
binary file attachments for executable programs, compressed file
archives, etc. |
| message |
rfc822 |
Indicates that the message part contains a complete RFC 822
compliant message, complete with headers |
| multipart |
mixed, alternative |
Indicates that this is part of a mixed message (a message
that contains multiple parts of different content types) |
The three most common content types that are used in applications are
text/plain for the mail message body, application/octet-stream for
binary file attachments and multipart/mixed for messages that contain
both text and attached files. For more information about the
different content types, refer to the Multipurpose Internet Mail
Extensions (MIME) standards document RFC 1521.