Schema Fields and Namespaces

[This is preliminary documentation and subject to change.]

When accessed through the Exchange OLE DB provider, item property names are scoped using a Uniform Resource Identifier (URI) namespace reference. By convention, each namespace URI falls within either the Uniform Resource Name (URN) or Uniform Resource Locator (URL) scheme. The full name of each property is comprised of a concatenation of the namespace URI prefix and the local property name.

An example of a property name using the URN scheme is the "To:" mail header field for messages. The full name of the property when accessed through the Exchange OLE DB provider is:

urn:schemas:mailheader:to

In this case, the namespace for the property is "urn:schemas:mailheader:" (a URI and a URN) and the local name is "to".

An example of the URL scheme is the property used when registering a store event sink to identify the sink's programmatic (ProgID) or class identifier (CLSID):

http://schemas.microsoft.com/exchange/event/sinkclass

In this case, the URI namespace is http://schemas.microsoft.com/exchange/event/ and the local name is sinkclass.