We currently do not offer an API function for sending email content through the API or for scheduling emails through the API. This is a feature request that our developers are looking into, though I can not give a time table on this feature being available. Please check back on the forums periodically as we post all new features here.
If this feature existed, we would definitely be using it for a project we're currently working on. I'll keep tabs on the forums.
"So shines a good deed in a weary world." - Willy Wonka