Our verdict: a compliant footer is cheap insurance
CAN-SPAM is a US law, and the FTC's compliance guide is the plainest official summary of it. It covers commercial messages, defined as email whose primary purpose is commercial advertisement or promotion, and the FTC says the law doesn't apply just to bulk email [1]. For most small-business newsletters that promote offers or services, the rules apply. This guide summarizes the FTC's guidance and is not legal advice; talk to a lawyer about your specific messages.
We would set up the footer, sender name and unsubscribe flow once, test them, and reuse them on every send.
The requirements in one table
| Requirement | What the FTC guide says | How to check your newsletter |
|---|---|---|
| Header information | Header information must be accurate and identify the person or business who initiated the message [1] | Sender name and address match your business |
| Subject line | The subject line must accurately reflect the content of the message [1] | Read the subject next to the body |
| Identify as an ad | Disclose clearly and conspicuously that your message is an advertisement [1] | Promotional messages are labeled in a way readers can see |
| Location | Include your valid physical postal address [1] | Street address, registered PO box or registered private mailbox in the footer |
| Opt-out notice | A clear and conspicuous explanation of how the recipient can opt out [1] | Visible unsubscribe link in every message |
| Honor opt-outs | Process requests for at least 30 days after sending; honor within 10 business days [1] | Test the link; confirm the address is suppressed |
| Others acting for you | You can't contract away your legal responsibility [1] | Review what agencies or platforms send in your name |
Footer and unsubscribe checklist
- Business name as readers know it.
- Valid physical postal address [1].
- One-line reason the reader is receiving the email, such as signing up on your website.
- A working unsubscribe link that requires nothing more than an email address or a single page visit; the FTC says you can't charge a fee or require personal information beyond an email address [1].
- No re-adding unsubscribed people through imports, and no selling or transferring their addresses [1].
- A test unsubscribe each month from a spare address, recording the date it stopped receiving mail.
Who needs this, and what CAN-SPAM does not settle
Any US business sending promotional email to customers, leads or other businesses should follow these rules [1]. Purely transactional or relationship messages are treated differently, but the FTC warns that the law views these categories narrowly [1], so a receipt with a big promotion can still count as commercial.
CAN-SPAM is not the only rule set. Other countries have their own email and privacy laws; Cloudflare's email documentation, for example, lists CAN-SPAM (US), GDPR (EU) and CASL (Canada) among the anti-spam rules senders must follow [3]. If you have subscribers outside the US, get advice for those places rather than assuming CAN-SPAM covers you. Mailbox providers add their own requirements too: Google requires senders of more than 5,000 messages a day to Gmail to support one-click unsubscribe and include a clearly visible unsubscribe link [2].
Worked example: counting the opt-out window
Hypothetical example: a bike shop sends a sale email on a Tuesday. A customer clicks unsubscribe that afternoon. The FTC's limit is 10 business days [1], which ends on the second Tuesday after the request if no holidays fall in between. The shop's platform suppresses the address immediately, which is better than the minimum. If the shop instead collected unsubscribes by reply and updated a spreadsheet weekly, a busy week could push it past the deadline.
Pitfalls and our decision rule
Our rule: do not send a promotional email until the footer has a postal address, the unsubscribe link has been tested, and you know who processes opt-outs. Penalties of up to $53,088 per violating email, per the FTC [1], make that ten-minute check worthwhile.
- Leaving the postal address out of a plain-text version of the email.
- A subject line that promises something the email does not contain [1].
- An unsubscribe link that breaks after a template change.
- Assuming the law only covers mass mailings; the FTC says otherwise [1].
- Relying on a vendor to comply on your behalf [1].
Questions before you decide
Can I use a PO box as my newsletter address?
The FTC's guide says the address can be your current street address, a post office box you've registered with the U.S. Postal Service, or a private mailbox registered with a commercial mail receiving agency under Postal Service rules.
Does CAN-SPAM apply to emails sent to businesses?
Yes. The FTC states that 'The law makes no exception for business-to-business email.' It also says the Act doesn't apply just to bulk email.
If my email platform handles unsubscribes, am I covered?
Not automatically. The FTC says you can't contract away your legal responsibility to comply with the law, so you remain responsible for messages sent on your behalf. Check that the platform's unsubscribe works and that your footer includes your postal address.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- FTC: CAN-SPAM Act: A Compliance Guide for Business Accessed 13 Oct 2026
- Gmail Help: Email sender guidelines Accessed 13 Oct 2026
- Cloudflare Docs: Email Routing limits (compliance note) Accessed 13 Oct 2026
Sources link directly to providers. Product buttons may use separately labeled affiliate links. Read our disclosure.