2.1 MIME Generation Algorithm Details

This section specifies both conversion to pure MIME messages and conversion to TNEF messages from Message objects.

When generating a MIME rendering of a Message object, whether a pure MIME message or a TNEF message, MIME writers retrieve all properties of the Message object by issuing one of the following remote operation (ROP) sequences:

  • RopGetPropertiesList ([MS-OXCROPS] section 2.2.8.5) followed by RopGetPropertiesSpecific ([MS-OXCROPS] section 2.2.8.3)

  • RopGetPropertiesAll ([MS-OXCROPS] section 2.2.8.4)

Clients can explicitly request conversion to a pure MIME message or to a TNEF message by doing one of the following. A MIME writer SHOULD return the message format requested by the client.

  • A client can request conversion to a pure MIME message for all recipients (2) by setting the value of the PidTagSendRichInfo property ([MS-OXOABK] section 2.2.3.18) to FALSE on the Message object, and request conversion to a TNEF message for all recipients (2) by setting the same property value to TRUE.

  • A client can request conversion to a pure MIME message for an individual recipient (2) by setting the value of the PidTagSendRichInfo property to FALSE on that recipient (2), and request conversion to a TNEF message for an individual recipient (2) by setting the same property value to TRUE.

  • A client can request conversion to a pure MIME message for a message sent using a one-off address by setting the M bit in the one-off EntryID, as specified in [MS-OXCDATA] section 2.2.5.1, and request conversion to a TNEF message by resetting the same bit.

Similarly, when conversion to a pure MIME message is requested, clients can explicitly request plain text or HTML message body generation by one of the following means. Again, a MIME writer SHOULD honor such a client request for message format.

  • A client can request a specific MIME body format for all recipients (2) by setting the value of the PidTagSendInternetEncoding property ([MS-OXOABK] section 2.2.3.19) on the Message object to one of the values in the following table.

  • A client can request a specific MIME body format for an individual recipient (2) by setting the value of the PidTagSendInternetEncoding property on the recipient (2) to one of the values in the following table.

The valid values of the PidTagSendInternetEncoding property are specified in the following table. The first value is the hexadecimal representation of the property value; the second is its representation in Augmented Backus-Naur Form (ABNF), as specified in [RFC5234].

PidTagSendInternetEncoding property value (hexadecimal, ABNF)

Requested format

0x00060000

%x00.00.06.00

Plain text only

0x000E0000,

%x00.00.0E.00

HTML only<1>

0x00160000,

%x00.00.16.00

Both plain text and HTML