The User hierarchy is reserved for users: a user may always use the

The libraries description says about the "User" hierarchy: portion of the

hierarchy which is formed from his/her email address as follows: replace the @ by a ., reverse the order of the components, capitalise the first letter of each > component, and prepend User.. For example, simonmar@microsoft.com becomes User.Com.Microsoft.Simonmar.

What if the username itself contains a '.'? (This is fairly common.) That could lead to ambiguity. For example, (perhaps) both "John.Smith@foo.com" and "John@smith.foo.com" translate to "User.Com.Foo.Smith.John". Dean Herington