If an email's main purpose is to advertise or promote a product or service, federal law requires a valid physical postal address of the sender. The CAN-SPAM Act doesn't say where in the email the address goes. A purely transactional email is exempt from most of the Act.
We read the CAN-SPAM Act at 15 U.S.C. §7702 and §7704, the Federal Trade Commission (FTC) rule at 16 CFR part 316, and the FTC's compliance guide for business. We also read the address rules of two email service providers, Mailchimp and Campaign Monitor. Below is what each text says, and where the platforms ask for more than the law does.
What CAN-SPAM requires in a commercial email
Under §7704(a)(5)(A), sending a commercial email is unlawful unless the message provides three things. The statute lists them this way:
"(i) clear and conspicuous identification that the message is an advertisement or solicitation; (ii) clear and conspicuous notice of the opportunity under paragraph (3) to decline to receive further commercial electronic mail messages from the sender; and (iii) a valid physical postal address of the sender."
In plain words, a commercial email must say it is an ad, tell readers how to opt out, and give a postal address.
Subparagraph (B) of the same subsection has one exception, and the exception names only the first item:
"Subparagraph (A)(i) does not apply to the transmission of a commercial electronic mail message if the recipient has given prior affirmative consent to receipt of the message."
Prior affirmative consent means, in our plain reading, that the reader agreed in advance to get the message. Subparagraph (B) doesn't mention the opt-out notice or the postal address. A subscriber who signed up still gets an email with both.
| Required item | Where in the statute | What the text asks for | Named in the consent exception of §7704(a)(5)(B)? |
|---|---|---|---|
| Ad label | §7704(a)(5)(A)(i) | "clear and conspicuous identification that the message is an advertisement or solicitation" | Yes |
| Opt-out notice | §7704(a)(5)(A)(ii), with the mechanism in §7704(a)(3) | Notice of the chance to stop further commercial email | No |
| Postal address | §7704(a)(5)(A)(iii) | "a valid physical postal address of the sender" | No |
How the opt-out has to work
Section 7704(a)(3)(A) describes the opt-out tool. The email must contain a working return email address or another internet-based mechanism, shown clearly. The tool must keep working "for no less than 30 days after the transmission of the original message."
A sender can offer a menu of email types in place of one switch. Section 7704(a)(3)(B) accepts a menu "…if the list or menu includes an option under which the recipient may choose not to receive any commercial electronic mail messages from the sender."
Once a request arrives, the sender has a deadline. Section 7704(a)(4)(A)(i) bars sending covered commercial email "more than 10 business days after the receipt of such request."
The FTC rule also limits what a sender can demand. Under 16 CFR 316.5, a sender may not "require that any recipient pay any fee, provide any information other than the recipient's electronic mail address and opt-out preferences, or take any other steps except sending a reply electronic mail message or visiting a single Internet Web page" to opt out.
Which emails need the address and which don't
The address rule applies only to a commercial email. Section 7702(2)(A) defines the term:
"The term "commercial electronic mail message" means any electronic mail message the primary purpose of which is the commercial advertisement or promotion of a commercial product or service (including content on an Internet website operated for a commercial purpose)."
The next paragraph, §7702(2)(B), takes one group out: "The term "commercial electronic mail message" does not include a transactional or relationship message." Section 7702(17)(A) lists five kinds of transactional or relationship messages, which we shorten here:
- Messages that confirm or complete a purchase the reader already agreed to make with the sender.
- Warranty, product recall, safety or security information about a product the reader uses or bought.
- Notices about a subscription, membership or account, such as a change in terms, a change in status, or a regular balance or statement.
- Information about a job or benefit plan the reader is part of now.
- Delivery of goods or services the reader is owed under an earlier deal, including product updates or upgrades.
The FTC rule sets a strict test for these messages. Under 16 CFR 316.3(b), a message is transactional or relationship "…if the electronic mail message consists exclusively of transactional or relationship content as set forth in paragraph (c) of this section."
Many emails mix a receipt with a promotion. For those, 16 CFR 316.3(a)(2) treats the message as commercial if either of two conditions is true:
"(i) A recipient reasonably interpreting the subject line of the electronic mail message would likely conclude that the message contains the commercial advertisement or promotion of a commercial product or service; or (ii) The electronic mail message's transactional or relationship content as set forth in paragraph (c) of this section does not appear, in whole or in substantial part, at the beginning of the body of the message."
The FTC guide shows the test with two emails. Both have the subject line "RE: Your Account Statement." The guide says "MESSAGE A is most likely a transactional or relationship message subject only to CAN-SPAM’s requirement of truthful routing information." The guide also says "MESSAGE B is most likely a commercial message subject to all CAN-SPAM's requirements." What decides the difference is the content that comes first in the body.
For a message that is purely transactional, the FTC guide says this: "If it contains only transactional or relationship content, its primary purpose is transactional or relationship. In that case, it may not contain false or misleading routing information, but is otherwise exempt from most provisions of the CAN-SPAM Act."
The FTC adds a warning about subscribers and members:
"Keep in mind that the law views these categories narrowly. That means you shouldn’t assume that any message you send to recipients who have an ongoing commercial relationship with you – including subscribers or recipients who participate in a membership program – are transactional or relationship messages."
Two more points from the texts help with unclear cases. A link alone doesn't decide the question. Under §7702(2)(D), a link to a company's website "does not, by itself, cause such message to be treated as a commercial electronic mail message" when the content shows another primary purpose. Selling to other companies doesn't change the rule either. The FTC guide says "The law makes no exception for business-to-business email."
What counts as a valid physical postal address
The FTC rule defines the phrase at 16 CFR 316.2(p). The definition allows three kinds of address: the sender's current street address, a U.S. Postal Service (USPS) post office box, or a private mailbox at a commercial mail receiving agency (CMRA). A CMRA is a business that receives mail for customers under USPS rules, as we explain in what is a CMRA.
The full text of the definition is in our post on using your home address as your business address. That post also walks through what each kind means for a founder who works from home.
The definition expects a post office box or private mailbox that the sender has "accurately registered" with USPS or with the mail receiving agency. For a private mailbox, that setup runs through USPS Form 1583 in our reading. Reasons the form gets sent back are in USPS Form 1583 rejected.
The rule doesn't ask for the place you work from
Some guides online say the footer address must be tied to an actual business location. We looked for that idea in the federal texts. We counted words in four documents on October 25, 2026, and each count used whole-word matching.
| Document we read | "footer" | "street address" | "private mailbox" | "business location" | "place of business" |
|---|---|---|---|---|---|
| 15 U.S.C. §7704 | 0 | 0 | 0 | 0 | 0 |
| 15 U.S.C. §7702 | 0 | 0 | 0 | 0 | 0 |
| 16 CFR part 316 | 0 | 1 | 1 | 0 | 0 |
| FTC compliance guide | 0 | 1 | 1 | 0 | 0 |
The phrases "business location" and "place of business" appear zero times in those four texts. The definition also allows a post office box, and a post office box isn't a place anyone works from. In our reading, the definition lists kinds of postal address and doesn't ask for your workplace.
The word "footer" also appears zero times. The law sets what a commercial email must contain and leaves the position open. Campaign Monitor explains why the address usually ends up at the bottom: "The most common position for placement is the footer of your template (or the bottom of your campaign content) because that's where people will scroll down to look for it."
One more correction to a common summary. Some lists give "sender identification" as the third required item. The statute's first item is identification of the message as an advertisement or solicitation. Naming the sender is a different thing.
How to write a mailbox address in an email footer
The two platforms we read agree on the basic test. Mailchimp says: "The address must be an address where you can receive mail, and can't be an email address or website." Campaign Monitor tells home-based businesses that "you must still supply an address; it just needs to be somewhere you can receive postal mail."
For a private mailbox, write the address in the format your mail center gives you. We cover the USPS format, including the PMB (private mailbox) or # designator and why a PMB isn't a post office box, in is your mailing address a PO box.
Look at the name above the address too. In our reading, a reader who mails you a letter will likely use the name printed in your footer. Your mailbox should be able to accept mail in that name.
Email isn't the only place your address shows. The rules for a website contact page are different, and we compare them in business address on your website.
Why your email platform asks for an address on every send
The law covers commercial email. Email platforms often ask for more. Mailchimp's footer article says "Anti-spam laws and our Terms of Use require you to include certain information in every email you send." Mailchimp's anti-spam page adds:
"You must include your contact information in every promotional email you send, including a physical mailing address or P.O. Box where you can receive mail."
Mailchimp also applies the U.S. law to every sender on its platform: "Emails you send through Mailchimp must comply with the U.S. CAN-SPAM Act , even if your business is outside the United States."
Campaign Monitor ties the rule to its own terms as well. The help page says "There are different anti-spam laws for different countries but the inclusion of an address is also necessary to comply with our terms of use." Campaign Monitor also says "Some content filters will also scan for an address and block emails that don't include one, so it's also good for deliverability." That claim is the platform's own, and we didn't test it.
Platform help pages can be narrower than the rule and can disagree with each other. The Campaign Monitor page we read mentions a post office box and doesn't mention a private mailbox. The FTC rule names both. Mailchimp's footer article suggests a post office box for home workers. A separate Mailchimp page on custom footers says to "enter your physical address (not a post office box) somewhere in the footer" if you don't use the address merge tag. The two Mailchimp pages point in different directions, so check the settings in your own account before you send.
What happens if the address is missing or wrong
The FTC enforces the Act. Section 7706(a) says the law "shall be enforced by the Commission as if the violation of this chapter were an unfair or deceptive act or practice proscribed under section 18(a)(1)(B) of the Federal Trade Commission Act ( 15 U.S.C. 57a(a)(1)(B) )."
As of this writing, the FTC's compliance guide states the cost per message: "Each separate email in violation of the CAN-SPAM Act is subject to penalties of up to $53,088, so non-compliance can be costly."
A missing address can also cause trouble with your email platform. Both platforms we read make the address a condition of their own terms.
This post explains the text of a federal statute, an FTC rule and the FTC's guide. The post isn't legal advice. Confirm how the rules apply to your emails with a lawyer.
How an Auteur address fits your email footer
We sell virtual mailboxes, so this is the seller's view. Auteur is in pre-launch, and your exact street address is assigned the day your city opens. We don't say any email platform will accept our address, and we don't promise that any address makes an email compliant. The FTC rule names a private mailbox at a CMRA as one kind of valid address. Your platform may apply its own rules.
The Virtual Business Address receives mail in a business or trade name. Choose it if the name in your footer is an LLC, a corporation or a DBA (doing business as) name. The Virtual Mailing Address is for personal mail, in individual names only. Choose it only if you send under your own name.
Both plans photograph the envelope of every piece as it arrives, and we open and scan only when you ask, for one flat fee per piece. Henry, our AI assistant, explains each letter you ask us to open. USPS Form 1583 is required before any provider can receive mail for you. Pricing comes by email with the next steps, and our fees and limits are in our fair use policy.
If your footer shows a business name, get your Virtual Business Address. Ordering is free, there's no card, and nothing is charged today. If you send under your own name only, the Virtual Mailing Address is the plan to choose.
FAQ
What should be included in an email footer?
If the email is commercial, federal law requires three items somewhere in the message. Under 15 U.S.C. §7704(a)(5)(A), the items are an ad label, notice of how to opt out, and "a valid physical postal address of the sender." The law doesn't name the footer as the place. The ad label isn't required if the reader gave prior affirmative consent.
Can I use a PO box in my email footer?
Under the FTC rule at 16 CFR 316.2(p), a USPS post office box is one of three kinds of valid physical postal address. The other two kinds are a current street address and a private mailbox at a commercial mail receiving agency. Mailchimp's anti-spam page also accepts a "P.O. Box where you can receive mail."
Do transactional emails need a physical address?
If an email contains only transactional or relationship content, the FTC guide says it "is otherwise exempt from most provisions of the CAN-SPAM Act." The message still may not carry false or misleading routing information. Under 16 CFR 316.3, a message that mixes in promotion can count as commercial. Your email platform may still require the address on every email.
Does a sender outside the US need a US address in the footer?
The federal texts we read don't answer that question directly. Mailchimp answers it for its own platform: emails sent through Mailchimp "must comply with the U.S. CAN-SPAM Act , even if your business is outside the United States." Other platforms may set different rules, so check the terms of the service you use.
Bottom line
The CAN-SPAM Act requires a valid physical postal address in every commercial email, along with an ad label and an opt-out notice. A message that is purely transactional is exempt from most of the Act. The law doesn't mention a footer and doesn't ask for your place of business. The FTC rule accepts a street address, a USPS post office box, or a private mailbox at a CMRA. Email platforms often ask for an address on every send, so read your platform's terms as well as the law.
