Intercepting Microsoft Exchange Mail Send Events

Are there any examples which show how to hook into an Exchange mail send event?

I would like to

1. Add marketing information to all emails sent through our Exchange server when they are going to an external address.
2. Start a workflow when emails a开发者_JAVA百科re sent

I know I could use transport rules to complete the first request, however this would need be implemented using .NET 3.5/4.0 and C# as it requires a custom GUI.