The Can-SPAM Law
The Can-SPAM law is actually quite vague, and has very little teeth in terms of prosecution. But, it really has three main “features” that should be obeyed:
Anyone can request to be taken off your list—and you must honor this request within 10 days. Every email sent must have this unsubscribe link.
If you don’t have “affirmative consent” from all your subscribers, you must label your email message as commercial or have a “Non-Confusing” subject line.
You must list your postal address on all outgoing email.