I routinely get a lot of emails with questions about the various stuff that I do. That was wonderful while I could keep up with the flow, but it is not something that can really scale up. As a rule, I have started to refer all such questions to the appropriate channels for them.
For NHibernate: The NHibernate forums
For Rhino Mocks: The Rhino Mocks Mailing List
For Rhino Tools: The Rhino Tools Developers mailing list
The reasoning behind this decision is very simple, I don't have the time to help everyone, and in all those places, there are other people that are doing great job answering those questions.
This also means that over time, there is a wealth of knowledge gathered there, so make a search first, to see if the question has already been asked.
As an exception to this, if you have a question about one of my posts, go ahead and send me an email about it.
If you really want me to help you, contact me about commercial support.