It woud be great to be able to send different emails based on the values submitted on a form. For example if a user selects an Enquiry Type of 'Complaint' they would receive a different automated reply to a user that submitted 'General Feedback'.
You could extend ActorsExecutingService and override GetFormSubmissionActors.
In the override, you could call:
base.GetFormSubmissionActors(submission, formContainer, formIden, request, response, isFormFinalizedSubmission).ToList();
Then check if the returned list contains a SendEmailAfterSubmissionActor. If it does, check the submitted data, and update the EmailTemplateActorModel's property ToEmails, and return the list.
Finally tell Episerver to use your implementation instead of ActorsExecutingService. Can be done using StructureMap.