CAN-SPAM Act: The Rules for Commercial Email

WHY IT EXISTS: The CAN-SPAM Act was created to establish a national standard for commercial email. It protects consumers from deceptive practices by giving them the right to opt-out of marketing messages and requiring senders to be transparent about who they are and what they're promoting.

THE MENTAL MODEL: Think of CAN-SPAM not as a law that stops spam, but as one that regulates it. It establishes the ground rules for any business sending promotional emails. The core principles are honesty in headers and subjects, clear identification as an advertisement, and honoring a recipient's request to be left alone. It's an opt-out framework, not an opt-in one.

HOW IT WORKS: The law outlines seven key requirements for any commercial email. First, your header information, including the "From" line and routing info, must be accurate. Second, the subject line must not be deceptive. Third, the message must be clearly identified as an advertisement. Fourth, you must include your valid physical postal address. Fifth, you must provide a clear and conspicuous way to opt out of future emails. Sixth, you must honor opt-out requests within 10 business days. Finally, you are responsible for the compliance of anyone you hire to do email marketing for you.

WHEN TO USE IT: Compliance with CAN-SPAM is mandatory, not optional. It applies whenever you send an email with the "primary purpose" of being a commercial advertisement or promoting a product or service. This includes newsletters, sales promotions, and even many B2B outreach emails.

WHEN NOT TO USE IT: The rules do not apply to "transactional" or "relationship" messages. These are emails triggered by a customer's action, like an order confirmation, shipping notice, or password reset. The footgun here is that if you add significant promotional content to a transactional email, it can cross the line and become subject to CAN-SPAM rules. The primary purpose of the message is the key test.

ONE CANONICAL EXAMPLE: A software company sends a monthly email to its user base announcing new features and promoting a paid upgrade. To comply, the email must have a non-deceptive subject line and include a footer with "This is a promotional message," the company's office address, and a one-click unsubscribe link. If a user unsubscribes, they must be removed from the list promptly.