Classification Properties

In order to preserve full client/server data fidelity in the MIME content, if the PidLidClassified property ([MS-OXCMSG] section is present in the mail object and is set to TRUE, then clients SHOULD<132> write the following header:

 X-Microsoft-Classified: true

In addition, clients SHOULD write header values for all of the X-Microsoft-Classification, X-Microsoft-ClassDesc, X-Microsoft-Classification-GUID, and X-Microsoft-Classification-Keep headers.

When the X-Microsoft-Classified header is present and has the value "true", MIME readers SHOULD map or copy all classification header values to their corresponding property values, as specified in the following table. If the X-Microsoft-Classified header is missing or has a value other than "true", MIME readers SHOULD NOT<133> set any of the five property values listed in the table.

Classification header name

Classification property name

Header value mapping


PidLidClassified ([MS-OXCMSG] section

"true" maps to TRUE.


PidLidClassificationKeep ([MS-OXPROPS] section 2.55)

"true" maps to TRUE.

"false" maps to FALSE.


PidLidClassification ([MS-OXCMSG] section

No mapping. The string value is copied directly.


PidLidClassificationDescription ([MS-OXCMSG] section

No mapping. The string value is copied directly.


PidLidClassificationGuid ([MS-OXPROPS] section 2.54)

No mapping. The string value is copied directly.