There are significant differences between Canada's anti-spam law, CASL, and the U.S. CAN-SPAM. Key differences include:<p>1. CASL is opt-in, while CAN-SPAM is opt out;<p>2. Canada has an opt-in exception for existing business relationships that must be renewed every two years; and<p>3. CASL applies not only to email but to any electronic message, including a message sent via an installed program.<p>For more information, see: <a href="http://www.mcmillan.ca/Files/172403_Key%20Differences%20between%20US%20and%20Canadian%20Anti-Spam%20Laws.pdf" rel="nofollow">http://www.mcmillan.ca/Files/172403_Key%20Differences%20betw...</a>