I've put a post on my blog explaining how you can add E-mail notifications to David Mudrak's Stamp Collection Module for Moodle 1.9. I'll be working on a version for Moodle 2.x. My blog post is here in case your institute is using the Stamp Collection. Or if you're just curious.
So what this now means is that every time a Stamp is awarded to a student, the student can receive an E-mail message from the Awarder automatically. The student can always disable his or her E-mail in Moodle to avoid receiving E-mails. The modified code that I have done (thanks David Mudrak for the original code!) respects that right to privacy. Give it a try by reading my blog post and let me know what you think.