Here is the USA we have what most would refer to as an opt-out email policy in which senders of marketing email are required to give the recipient a clear method to unsubscribe or opt-out of future emails from the sender. Last year Canada passed the FISA (Fighting Internet and Wireless SPAM Act) which requires that senders obtain permission from the recipient before sending any emails at all. This is generally referred to as an opt-in email policy.
This is generally encouraged by professionals in Email Marketing anyway. Only sending email to people who have originally requested it, is a way to keep SPAM reports low and delivery high. Having an opt-in policy also guarantees that you will never accidentally input an incorrect email address. Finally, my favorite thing about opt-in policies is that they allow you to go so far as to track the IP address used when subscribing to a list. This acts as strong back up to any claims that you are sending unsolicited email.
If you do regular advertising or marketing with Canadian consumers this would be a good time to double check your current systems and policies. Make sure you are compliant.