Inside Microsoft Dynamics GP takes a look at customized messages in email in Dynamics GP 2010. Email messages can be assigned at the document level so all vendors or customers get the same message for a document. I can see this being useful for things like P.O. terms that everyone wants to accompany a document. Messages can also be assigned to a customer/vendor and document combination to accommodate specific needs or requests. There is more on this at Inside Microsoft Dynamics GP.