The killer app would be to combine mail from snail mail & email into a single product. For the snail mail side, some OCR, recognizing places/dates/etc. (the way

The killer app would be to combine mail from snail mail & email into a single product. For the snail mail side, some OCR, recognizing places/dates/etc. (the way gmail does), & attaching images of the snail mail to the thread should satisfy that use case. All that would be needed after that would be a simple label to designate the snail mail. Voila, you can refer to everything as mail.