188.8.131.52 from_mapi_tlh Attribute
Type: bool (section 2.2.20)
Description: The from_mapi_tlh attribute indicates that the entity for which this security descriptor applies is from a message store that is accessible by using WebDAV clients that have the Messaging Application Programming Interface (MAPI) enabled.
The absence of this attribute implies that its value is 0. This attribute is applicable only when it is set by the WebDAV server. The WebDAV server MUST ignore this attribute if it is set by a client.