For small-business owners trying to compete for customers in what sometimes feels like an over-saturated market, every action could be “make-or-break” for his or her business. And, with many of them operating on such a small marketing budget, options are usually limited.

One of the most cost-effective ways for owners to keep business is via email marketing, which allows businesses to keep customers up-to-date on its latest sales at little or no cost. Most already know this and take advantage of it on his or her own with a monthly e-newsletter or a one-to-one email that promotes products or services, but many of them do not realize that he or she may be doing incorrectly and illegally.

In 2003, the United States Congress passed the Controlling the Assault of Non-Solicited Pornography And Marketing Act, or CAN-SPAM Act for short, which legislates how and when businesses can send commercial email messages to current or potential customers. According to the Federal Trade Commission, this includes any emails with the primary purpose to advertise or promote a commercial product or service, including content on a website operated for a commercial purpose.

If it is determined that the CAN-SPAM Act must be followed, there are a few simple steps to ensure the law is not broken.

First, businesses need to send emails to only those who opt-in to receiving them, whether they subscribed via a sign-up form on the business’ website, wrote down their email address at a trade show or verbally gave permission to the owner or official representative for the business. Their doing business with the company or being known personally are not viable legal reasons.

Second, the CAN-SPAM Act requires a functioning opt-out mechanism by which email recipients can unsubscribe his or her email address from future email messages. Companies can place it at the top, side or bottom, but the law requires it to be there. Businesses must then add the unsubscribed email addresses into a “suppression list” within 10 business days and never send a commercial email message to that address again unless authorized by the customer.

There are other requirements for the CAN-SPAM Act that, while seem obvious, are sometimes overlooked. These include making sure the “From,” “To,” “Reply-To” and routing information are accurate, not using deceptive subject lines and telling the recipient where you’re located—this can be a current street address, a post office box or a private mailbox that’s registered with a commercial mail receiving agency established under Postal Service regulations.

So, should small businesses really pay attention to the CAN-SPAM Act?

Unfortunately, the size of a business is not a factor. The requirements of the Act are straightforward, and the penalties could be severe for the owner if convicted. In fact, each separate email that violates the CAN-SPAM Act is subject to penalties of up to $16,000 with no exceptions. And, although it may seem like it’s not a “big deal,” the FTC reports receiving over 130,000 complaints per day or nearly 5 million per year.

To learn more about the CAN-SPAM Act to ensure that emails do not get flagged as SPAM or junk by readers, read the guidelines that are found at the Federal Trade Commission’s Bureau of Consumer Protection website.