Any possible way to send out Email Notification of completed snapshots?
Not natively, yet. There is a proposal to add some sort of notification system to Kopia. See DESIGN: Support for notifications in Kopia · Issue #1958 · kopia/kopia · GitHub
I should also mention, Kopia supports before/after snapshot actions, so you could potentially write your own email notification script that runs automatically after a snapshot has been completed. See