Permission comes first
Email and SMS reach people in personal spaces: their inbox and their phone. That is why most countries treat them differently from, say, a banner ad. Marketing permission means the recipient has agreed, in a way you can show, to receive your messages. This article covers the general principles. It is not legal advice, and the rules for email, text messages and other channels vary by country and change over time, so check what applies to you.
Why rules differ between email and SMS
Many places regulate the two channels separately. Text messages are often treated more strictly, partly because they feel more intrusive and sometimes cost the recipient money. Some regions require prior agreement for both; others allow certain messages to existing customers with an opt-out; some have specific rules for business-to-business messages. Do not assume a rule you read about for one country, or one channel, carries over to another.
What is common across most systems is a short set of ideas: the sender should be identifiable, the person should know what they are signing up for, and they should be able to leave.
What clear permission looks like
Plain sign-up wording
Tell people at the point of sign-up what they will receive and roughly how often. “Get our monthly newsletter with practical tips” is clearer than “Stay in touch”. If you plan to send both email and text, say so separately instead of folding one into the other.
An active choice
Good practice is for the person to do something deliberate: type their address and press a button, or tick an empty box. Pre-ticked boxes and consent bundled into accepting terms and conditions are the kind of design many regulators look at critically. Good form design helps here because a clear form is less likely to produce confused sign-ups.
One purpose at a time
If someone downloads a guide, that does not automatically mean they want a weekly sales email. If you offer a lead magnet, state plainly that signing up for it also adds them to a list, and let them decline that part where practical.
Records
Keep evidence of when and how each person agreed: the date, the form or page they used, and the wording shown at the time. If a complaint or question arises, a record is far more useful than a recollection. Keep this record only as long as it is useful, and treat it as personal data like anything else.
Confirmation steps
Some senders send a confirmation message after sign-up and add the person only once they respond. This is the idea behind double opt-in. It helps confirm that the address belongs to the person who entered it and can improve the quality of a list, though it adds a step and some people never confirm. Whether it is required depends on local rules, and whether it is wise depends on your audience. For SMS, a reply-to-confirm step is a common way to show intent.
Making it easy to leave
Every message should offer a simple way out. For email this usually means a visible unsubscribe link that works without logging in. For SMS it is often a reply keyword, with instructions included where required. A good unsubscribe process takes effect promptly, and you should avoid asking for reasons or extra steps before honouring it. Many laws specify a time limit, which varies, so check yours.
Making exits easy also protects you. A person who cannot find the unsubscribe link may click the spam button instead, which can damage sender reputation and, over time, email deliverability.
Existing customers and purchased lists
Having someone’s email address from a purchase does not always mean they agreed to all marketing. Some laws permit limited marketing to existing customers for similar products, usually with an opt-out; others do not. Read the rule for your market rather than guessing.
Buying or renting lists of contacts who never heard of you is risky in many places and tends to produce poor results anyway: complaints, bounces and low engagement. It is best avoided. Scraping addresses from websites is generally a bad idea for the same reasons.
Respecting choices over time
Consent is not a one-off event. Practical habits include:
- Suppress unsubscribed people across every list and tool, so one opt-out is not undone by a later import.
- Offer preference options, such as fewer messages or a single topic, as an alternative to leaving entirely.
- Review dormant contacts. Good list hygiene means removing people who stopped engaging rather than mailing them indefinitely; a short win-back campaign can be a polite last attempt.
- Keep sign-up wording and your actual practice in line. If you promised monthly emails, do not send daily ones.
Automation and consent
Marketing automation makes it easy to send many messages quickly, which is exactly why permission matters. Triggered messages, such as a welcome series, should still only go to people who agreed to receive them, and the content should match what they were told. Some triggered messages, like order confirmations, are transactional rather than promotional and may fall under different rules. The line between the two is not always obvious, and sending promotional content inside a transactional message can create problems.
A short checklist
- Does the sign-up form explain what, who and how often?
- Is the agreement an active choice, with email and SMS handled clearly?
- Do you store when and how each person agreed?
- Does every message identify you and offer a working opt-out?
- Are unsubscribes honoured quickly and everywhere?
- Have you checked the current rules in the countries where your recipients live?
Outcomes vary, and following good practice does not guarantee compliance with every law. When a situation is complicated, such as international audiences or sensitive data, take proper advice.