Thanks: I have multiply type of Email routes: smtp, company email web service and external Exact Target.
Here is an update: I got the Custom Email Provider route working this morning. I am able to intercept, now working on the Exact target call.
It would be nice if the Send Mail step in the Marketing automation would allow picking of the smtp server/service. Looking at determining the route in the custom email provider now. Maybe look for some type of variable (subject name or something in the template markup) in the template to pick the email path.