Hi David,
We've done this and it works great.
When doing this you have two choices, adding a document which has been created earlier in the action sequence using the Generate report action or adding a document which the user can choose from a drop down on the screen. The key to the second is to identify that document by record ID and then reference the actual document itself with an ActionResult, (which is stored in the Document field in the DocumentLibrary table) in the attachment field on the Send Email action.
Victoria Cameron
vcameron@cloudconsutlancyllc.com
www.cloudconsultancyllc.com
650/209-0345