The current version of the BedBooking application automatically send e-mails to clients only in one case - when your customer makes a reservation using the BedBooking widget. For other actions (e.g. changing a status from "No payment" to "Deposit paid"), it is currently not possible to automatically configure sending message templates. In such cases:
1) open your client's reservation.
2) select your preferred template,
3) send an e-mail manually.