CASL is the Canada Anti-Spam Law, it took effect in 2014 but you still have until July 1st 2017 to comply. It applies to any CEM (Commercial Electronic Message), sent to or from computers in Canada.
This is a move to ‘protect Canadians while ensuring that businesses can continue to compete in the global market place’, which also continues the global legislative changes concerning a need for express consent from individuals receiving marketing communications.
What happens if I don’t comply?
Fines of $1-10M per violation; with individuals and companies responsible and liable. At the end of the transition period any individual will be able to sue. However, during the transition, Canadian Government departments may investigate those they believe are not adhering to CASL.
The most important exemption are messages sent on behalf of a charity or political organisation that aim to raise funds and gain contributions. Though it is worth noting, if you send emails from the UK or Europe this exemption could be in violation of proposed changes for 2016.
You can read more about it here.