Seven email rules your business must follow by law

If you send marketing email to customers or prospects, federal law requires you to follow specific rules about what goes in those messages. The CAN-SPAM Act covers all commercial email – not just bulk blasts, but any message whose main purpose is to advertise or promote your product or service. Each email you send that breaks the law can cost you up to $53,088 in penalties. The good news: compliance is straightforward if you know what to include.

Key facts

• The law applies to all commercial email, including business-to-business messages and emails to existing customers.
• Each violation can trigger penalties up to $53,088.
• The primary purpose of an email – determined by its subject line and what appears first – decides whether it must comply with all CAN-SPAM rules or only some.
• Emails that are purely transactional or relationship-based (like order confirmations or account statements) have fewer requirements than promotional emails.

Tip 1: Know which emails are actually commercial

Not every email your business sends is a "commercial" email under the law. An order confirmation, invoice, or account statement to an existing customer is transactional. A message announcing a sale or promoting your services is commercial. The difference matters because transactional emails have fewer legal requirements. If you send an email that mixes both – say, an account statement with a sales pitch – the law looks at what comes first and what your subject line suggests. If the promotion is prominent or the subject line hints at a sale, the whole email is commercial and must follow all the rules.

Tip 2: Put transactional content at the beginning if you mix messages

When you send an email that includes both account information and a promotional offer, lead with the account information. If a customer opens an email about their order status and sees the order details first, followed by a small mention of your new product line at the end, the email is likely transactional. If you flip it – promotion first, order details buried below – the law treats the whole email as commercial. The position and prominence of content matter as much as the content itself.

Tip 3: Write subject lines that match the email's real purpose

Your subject line is the first thing the law examines. If your subject line says "Your Account Statement" but the email is really a sales pitch for a new product, you have violated the law. A customer reading your subject line should accurately understand what the email contains. If you're sending a promotional message, your subject line should reflect that. This protects you legally and builds trust with your customers, who won't feel tricked when they open the message.

Tip 4: Include your real business identity and address

Every commercial email must clearly identify who you are and where you are. Use your actual business name, not a vague or misleading sender name. Include a physical mailing address – a street address where recipients can reach you. This seems basic, but many small businesses skip it or use generic labels like "Marketing Team" instead of their real company name. The law requires recipients to know exactly who sent the message and how to find you.

Tip 5: Make your unsubscribe option obvious and easy

Every commercial email must include a clear, working way for recipients to opt out of future messages. This can be an unsubscribe link or a reply-to address where they can request removal. Don't bury it in tiny text at the bottom. Don't make them jump through hoops. When someone asks off your list, remove them from future mailings. This is not optional – it's a core requirement of the law.

Tip 6: Never use false or misleading routing information

This applies to all commercial email, even transactional ones. Your "From" address, "Reply-To" address, and routing information must be accurate. Don't use a fake sender address or a reply-to that goes nowhere. Don't use a domain name that doesn't belong to you or your authorized agent. Customers should be able to reply to your email and reach you, or at least reach someone who can help them.

Tip 7: Honor your unsubscribe requests promptly

When a customer clicks unsubscribe or asks to be removed from your list, stop sending them commercial email. This is non-negotiable. Some small business owners worry about losing the relationship, but ignoring an unsubscribe request is one of the easiest ways to trigger an FTC investigation. Build your email list on willing recipients, not on people trying to escape your messages.

What to do this week

Audit your last five marketing emails. Check that your sender name is your real business name, that your physical address appears somewhere in the email, and that an unsubscribe link is visible. If you send mixed emails (transactional plus promotional), make sure the transactional content comes first. Review your subject lines to confirm they accurately describe what's inside. If any email fails these tests, update your email template before you send the next batch. This takes an hour and eliminates most of your legal risk.

Sources

• CAN-SPAM Act: A Compliance Guide for Business - FTC

They did the reporting. The writing and the opinions here are ours.