Q. Does Microsoft Exchange Server 2007 incorporate a disclaimer for email, and does this work for internal as well as external (outbound) emails?
A. Yes, Exchange 2007 does support disclaimers for both internal and external email. To create disclaimers, you use transport rules on the Hub Transport servers. You can be quite flexible, adding a message to internal and external or one or the other type of mail. You can also have different disclaimers for different groups of users (business units).
One thing to remember is to set an exclusion so that once a disclaimer has been added once, it doesn’t continue to get added (during a mail conversation). For more information about Exchange 2007 disclaimers, see the Microsoft TechNet article, "Overview of Disclaimers."