Both :) I'd love the option to pass configuration through the subject or message body, but configuring defaults in an account would save typing them in every time. Options like automatic crop, deskew, and perspective correction would be essential.
I'm not sure what libs you're using for image processing, but OpenCV has a lot of this type of functionality.
Thereby putting Visio out of business, except as a reader. Definitely a win! Also, Microsoft would probably pay big-$$$ just to bury something like that (possibly putting it into use later in a web app).
I don't want to be a downer, but the last time I looked into OCR it was a real bucket of hurt, and that was on non-hand-drawn images (checking if text rendering worked).
Something less human-readable might be easier to handle (e.g. print out something analogous to a bar code and stick that anywhere on the whiteboard). Tie that bar code to a list of recipients and you're set.