Email-to-Text Gateways: CAN-SPAM’s Wireless Rule and the TCPA

A marketing message sent as email to a phone’s text gateway is still a message on someone’s cell phone, and two sets of rules can apply to it. The FCC’s wireless rule under the CAN-SPAM Act requires the recipient’s express prior authorization for commercial messages sent to wireless devices. The TCPA applies to texts regardless of how they are delivered. A company that treats email-to-text as a loophole is likely to be wrong on both counts.

What is an email-to-text message, and why does it matter?

Carriers operate email gateways that deliver a message addressed to a phone number at a carrier domain as a text on the phone, and the FCC rule below is built around that arrangement. A sender can use the route to send texts without a texting platform. From the sender’s side it looks like email. From the recipient’s side it looks like a text message.

That difference is the reason the law has a separate rule. Congress told the FCC to write rules to “protect consumers from unwanted mobile service commercial messages” in 15 U.S.C. § 7712, and defined that term as “a commercial electronic mail message that is transmitted directly to a wireless device that is utilized by a subscriber of commercial mobile service.” The same section makes clear that the CAN-SPAM Act does not displace the TCPA: “Nothing in this chapter shall be interpreted to preclude or override the applicability of section 227 of title 47.”

What does the FCC’s wireless rule require?

The rule is 47 C.F.R. § 64.3100. Its first requirement is permission: “No person or entity may initiate any mobile service commercial message” unless that person has “the express prior authorization of the addressee,” or one of a few narrow exceptions applies.

The rule defines the covered message. A mobile service commercial message is “a commercial electronic mail message that is transmitted directly to a wireless device that is utilized by a subscriber of a commercial mobile service,” and the rule adds a presumption: “A commercial message is presumed to be a mobile service commercial message if it is sent or directed to any address containing a reference, whether or not displayed, to an Internet domain listed on the FCC’s wireless domain names list.” In plain terms, an email to a carrier’s gateway domain is presumed to be covered.

The rule also has operating requirements. Under paragraph (b), a sender must “Cease sending further messages within ten (10) days after receiving such a request by a subscriber,” include “a functioning return electronic mail address or other Internet-based mechanism” for opt-out requests, and “Identify themselves in the message in a form that will allow a subscriber to reasonably determine that the sender is the authorized entity.” The same paragraph says the opt-out option must not “result in additional charges to the subscriber.”

There’s one exception worth knowing about. The rule says the prohibition doesn’t apply if the address “does not include a reference to a domain name that has been posted on the FCC’s wireless domain names list for a period of at least 30 days before that message was initiated, provided that the person or entity does not knowingly initiate a mobile service commercial message.” That protects a sender who emails an address that isn’t on the list, but it gives no cover to someone who knows the address reaches a phone.

How does the TCPA apply to the same message?

Separately from the CAN-SPAM rule. The FCC said in its 2003 order that the TCPA’s prohibition on autodialed and prerecorded calls “encompasses both voice calls and text calls to wireless numbers including, for example, short message service (SMS) calls, provided the call is made to a telephone number assigned to such service.” That is paragraph 165 of the FCC’s 2003 Report and Order.

Whether an email-to-text message triggers the autodialer provision depends on the equipment. In Facebook, Inc. v. Duguid, the Supreme Court held that an autodialer is a device that “must have the capacity either to store a telephone number using a random or sequential generator or to produce a telephone number using a random or sequential number generator.” An email tool that sends to a stored list probably doesn’t qualify.

That doesn’t end the analysis. A marketing message to a cell number can implicate the Do Not Call and quiet-hours rules, which apply to telephone solicitations, and state laws may apply to texts whatever way they are sent. The practical point is that using email as the transport doesn’t make the message something other than a text to the person who receives it.

How should a business use email-to-text safely?

I’d start by asking whether to use it at all. A texting platform built for the purpose records consent, handles STOP replies, and keeps logs. A bare email-to-text route may have none of that, and it leaves you exposed under both sets of rules with no records to defend yourself.

If a team does use it, three habits matter. Treat any gateway address as a phone number, which means the recipient’s consent must cover a text, not just email. Keep the opt-out mechanism the rule describes, and make sure it works from the phone, since the recipient may have no easy way to reply to an email. And keep the sending logs, because an email system can delete them on a schedule shorter than the one a lawsuit requires.

What happens if the recipient says they never agreed to a text?

Then the record decides. The FCC’s wireless rule asks for the addressee’s express prior authorization, and a sign-up that covers email marketing may not mention texts at all. A recipient who gave an email address on a website and later received a message on a phone will say the authorization was for email. The company’s answer is the sign-up page as it existed on that date, the exact language the person saw, and the routing that sent the message to a phone.

I’d also expect a plaintiff to ask how the company got a phone number into an email system in the first place. Tools that convert a phone number into a gateway address require someone to have collected the number, so the intake form, the source list, and the date become the questions. A company that built gateway addresses from numbers collected for another purpose, such as appointment reminders, has a scope problem as well as a rule problem. The earlier post on how far a phone number’s consent reaches covers that issue, and it is where I’d start the analysis.

What to preserve when an email-to-text claim arrives

1. Capture the email and CRM logs for the address, including the full headers and the carrier domain.
2. Pull the consent record, including what the recipient agreed to and whether the language mentioned text messages.
3. Export the opt-out requests and responses, with dates, for the address and the phone number.
4. Identify the tool that sent the message and the contract that covers its logs and retention.
5. Wait to respond to a demand letter or contact the recipient until a lawyer has reviewed the file.

The firm’s California TCPA defense lawyers page describes how these claims move through court. For related reading, see the earlier post on AI text chatbots and conversational SMS and on CTIA rules and 10DLC registration.

Questions businesses ask about email-to-text marketing

Is email-to-text exempt from the TCPA because it starts as email?

No. The FCC has said the TCPA’s prohibitions reach text calls to wireless numbers, and the message arrives as a text. Whether a particular message triggers the autodialer provision depends on the equipment, but the delivery route doesn’t create an exemption.

Do we need separate consent for email and text?

I’d get it. A person who agrees to marketing email hasn’t necessarily agreed to a text, and the wireless rule asks for express prior authorization for messages sent to a wireless device. Say so in the sign-up language.

What is the wireless domain names list?

It’s the FCC’s list of Internet domains that carriers use for messages delivered to phones. The rule treats a message sent to an address with a listed domain as presumptively covered. Check the FCC’s current list before you rely on any domain being outside it.

Can we send transactional messages by email-to-text?

The rule’s definition of a commercial electronic mail message excludes “a transactional or relationship message,” but the TCPA side can still apply, and you should keep promotions out of anything you rely on being transactional.

Defending claims over messages sent through gateways

If your company has been sued or received a demand letter over marketing messages sent by email to text gateways, the sending tool’s logs and the consent record will decide much of the defense. Rosenberger + Kawabata represents businesses defending TCPA lawsuits and class actions through its business litigation practice, including claims involving text messages sent through nonstandard channels. Contact Rosenberger + Kawabata online for a free and confidential consultation, or call (310) 894-6921.

Sources

The statutes and rules are 15 U.S.C. § 7712, 47 C.F.R. § 64.3100, and the Telephone Consumer Protection Act at 47 U.S.C. § 227. The FCC order is Rules and Regulations Implementing the Telephone Consumer Protection Act of 1991, Report and Order, FCC 03-153 (July 3, 2003).

The court decision is Facebook, Inc. v. Duguid, 592 U.S. 395 (2021).

This post is general information about the Telephone Consumer Protection Act and related laws as of May 1, 2026. It is not legal advice, and reading it does not create an attorney-client relationship. Courts and the FCC change the rules in this area often, and the outcome of any claim depends on its facts. Past results do not guarantee future outcomes.