Making sure the people who get your marketing emails have explicitly asked to receive them is best practice anyway. But a new anti-spam law going into effect in Canada over the next few months makes it even more of a necessity. And, yes, it could impact small businesses in the U.S. too — if you email regularly to customers in Canada.

The Canadian Anti-Spam Law goes into force officially on July 1, 2014.

The new legislation is technically designed to protect Canadian citizens against particularly nasty spam messages used for phishing, identity theft and spyware.

Unless you use the proper precautions, your business could be found in violation. And you could be open to penalties of up to $10 million (in Canadian Dollar rates) and even private civil suits. The law applies even if you are located outside of Canada, but send to recipients who access the messages from within Canada.

In a nutshell, the law applies to all commercial electronic messages including email, text messages, social media, IM and voice messages. The law is much broader than its U.S counterpart, the CAN-SPAM Act, which has been in effect for a number of years.

Email marketing company Cakemail created the following helpful chart (and a CASL compliance guide) comparing the new Canadian anti-spam law with the U.S. CAN-SPAM law:

We also asked other email marketing companies what they are recommending for the new law.

In an email interview with Small Business Trends, Connie Sung Moyle, manager of public relations and digital strategy at San Francisco-based email marketing company VerticalResponse, explained:

“Our customer support team has fielded a few inquiries from customers, and we’re telling them to consult with a legal advisor to make sure they’re fully cooperating with the new law.”

The new regulation gives a three year grace period for email marketers to obtain permission from recipients they already email inside Canada.

However, after that time the Canadian government will be able to file suit for up to $10 million against violators. Even Canadian citizens will be empowered to bring suit against you and your business for a violation, warns Chandler, Ariz.-based email and sales software services provider Infusionsoft.

In a recent post for users on the official Infusionsoft blog, product marketing specialist Justin Topliff added:

“Because it may be difficult to determine which contacts in your database are located in Canada, Infusionsoft encourages you to obtain a double opt-in from your entire database. This is a best practice for email marketing and will ensure you are in total compliance with all Canadian and U.S. spam laws on this issue.”

Meanwhile Constant Contact, the Waltham, Mass.-based company whose online marketing toolkit includes email and other services, says it is focusing on educating customers about the law. Lisa Kember, the company’s Regional Director for Eastern Canada explains:

“We are proactively reaching out to our customers — both those in Canada and those that market to Canada — to help guide them through the process of being CASL compliant.”

Constant Contact plans to hold webinars in June about the impending law and is offering new templates to make gaining customer consent easier.

Editor’s note: an earlier version of this article neglected to credit Cakemail for the chart.