As a sender based in either the United States or another country other than Canada, you still need to comply with certain aspects of the new Canadian anti-spam law (CASL).
The good news is that if you are already complying with CAN-SPAM, or the anti-spam law of your country, and are already adhering to other emailing best practices, such as requiring genuine, verifiable opt-in, then you are already in compliance with the requirements of CASL, for the most part.
The primary differences between the Canada Anti Spam Law (CASL) and the United States’ CAN-SPAM, is that the CASL requires genuine opt-in, and it requires that the contact information within the email remain a viable way to contact the sender for at least 60 days.
Of course there are lots of other requirements to the new CASL, but for the most part, with respect to sending email only, those requirements are essentially the same as the combined requirements of CAN-SPAM, and email best practices.
A secondary difference is that if you violate the CASL, there is a private right of action. What that means is that if you send an email that violates CASL to someone in Canada, they can sue you, and recover damages against you, even if you are outside of Canada.