The Canadian Radio-television and Telecommunications Commission recently released a guide on the anti-spam legislation that was passed in 2010 (although is currently not in effect yet)
You can read the guides here and here but a key take away involves how your opt-in and opt-out processes work.
The assumption of consent is something we have seen a lot with senders that end up having delivery issues.  So despite the legislation we do suggest making the opt-in process require they check a box in addition to an opt-in email.
By having a checkbox pre-selected and/or not using an opt-in email to verify the subscription you are opening yourself up to a poor quality list.