Supports mail merging to SMS or Email notification.

Be aware of anti spam legislation (Spam Act 2003). You need to provide users an ability to opt out. A simple solution is to define a customer account customer field for Mailer (Y|N). And implement a miner rule test i.e. Mailer: /N. Later versions of c9 will include a check box opt-out option on accounts that will make configuring this sort of thing easier.

Goto Setup, accounts. And type in Mailer (Y|N) as a custom field.
Now in miner, whenever you mine for purposes of sending email/SMS; check this flag.
Explicit yes: Y
Not no: /N