Anti-spam policy

An initiative at my company is planning to employ tactics that I feel are uncomfortably close to being spam. We’re not selling anything, but mass emailings to entire address books seems shady.

It falls to me and one or 2 others to develop a corporate policy on this issue and I’m having a hard time. I don’t want to just comply with the letter of the law, but figuring out where to draw the line is turning out to be very difficult.

Does anyone have an anti-spam policy for a non-ISP business? or any other tips on putting together an ethical policy?