engine - 2:22 pm on Dec 13, 2011 (gmt 0)

Engine would love to send my customers an email but I have a privacy policy that prohibits this unless they agree and most don't.

But if it's in relation to their previous order, thanking them for the order with a reward, that's not spam. Offer them the opportunity to agree to receiving special offers with that follow up e-mail. If they don't agree, no problem, move on to the ones that have agreed.