Its legal in the US so long as you follow the CAN-SPAM rules:

Federal rules require the following for commercial email sent to your mobile phone:

- Identification – The email must be clearly identified as a solicitation or advertisement for products or services;

- Opt-Out – The email must provide easily-accessible, legitimate, and free ways for you to reject future messages from that sender;

- Return Address – The email must contain legitimate return email addresses, as well as the sender’s postal address.

http://www.fcc.gov/guides/spam-unwanted-text-messages-and-em...

E-mailing Canadians for marketing purposes is definitely illegal now due to CASL legislation (Canada Anti-Spam Law) passed this year.