Updated: 7 November 2026 · Email Marketing · Guide
"Mailing" is the Spanish term for sending a commercial message to a list of contacts, by email or, in its classic form, by post. For a local business it almost always pays off with customers you already have (reminders, seasonal promotions, asking for a review) and almost never as a way to win over strangers. There is also a legal condition that is not optional: to send advertising by email in Spain you need the recipient's consent or an existing relationship with them, and you must offer a simple way to unsubscribe in every message.
For context: I'm Adrián Rubio and I offer email marketing from €200/month, so I have an interest in you hiring me. That is why I include when it is not worth it for you. I also take no commission on any tool.
What mailing is and how it differs from other terms
People use these terms as synonyms, but they are not quite the same:
- Mailing: sending a commercial message to a list. It can be by post or by email. In English the closest idea is "bulk email" or a "mailshot".
- Emailing: the same thing, but always by email. It is the usual form today.
- Newsletter: a periodic send of content (news, tips, offers) to people who have subscribed.
- Cold email: a message to someone who doesn't know you and hasn't asked for anything. It is the most delicate, both for results and for the law.
- Email marketing: the whole strategy: list, segmentation, automations and measurement. I cover it in more detail in where to start with email marketing.
"Mailing" is the term people search for most in Spanish, but what a local business almost always needs is a simple newsletter or an automatic reminder, not a mass campaign.
Types of send: to whom, what the law requires and when to avoid it
| Type of send | To whom | Consent needed? | What it is for | When to avoid it |
|---|---|---|---|---|
| Appointment reminder or service notice | Customers with an appointment | It is not a commercial message if it only gives appointment details | Reducing no-shows | If you add advertising, it becomes commercial |
| Newsletter or promotion to customers | Customers who have agreed to it | Yes, or an existing relationship with a similar product and an opt-out option | Getting them back, seasonal offers, reviews | If the list is old or bought |
| Mailing to a list that subscribed to you | Website form subscribers | Yes, express consent | Content, offers, notices | If there is no clear way to unsubscribe |
| Cold email to businesses or individuals | Strangers | Yes: without consent or a prior relationship, you cannot send advertising | Almost nothing for a local business | Whenever you cannot prove permission |
The short rule is this: if they haven't asked to receive your advertising and they aren't your customer, don't send it by email. Phoning or visiting in person are different routes with different rules.
When it pays off for a local business
It pays off when you already have contacts and a reason to talk to them again:
- A check-up or renewal reminder: clinics, hairdressers, garages, accountancy firms.
- A seasonal promotion to customers who have already bought.
- Asking for a review after a service. See how to ask for Google reviews without being awkward (in Spanish).
- Reactivating people who haven't been in for a while. You can automate it: email automations to win back customers (in Spanish).
It doesn't pay off when:
- You don't have a list yet: first you have to collect contacts with permission.
- Your typical customer buys once in a lifetime (a full home renovation, for example): there is no reason to write to them every month.
- You expect email to bring you new customers by sending to strangers. For that, being well placed on Google and on the map is more effective.
What results to expect: no invented figures
I'm not going to give you a "good" open rate, because today it is an unreliable figure: several email apps (Apple's, for example, with its privacy protection) load messages in advance, so opens come out inflated. Market figures also vary a lot by sector and list size, and I have no figures of my own from sends to customers that I can publish with confidence.
What I do recommend measuring, in this order:
- Replies and appointments or sales that come through the email. It is the only thing that pays the bills.
- Clicks on the specific link (book, call, see the offer).
- Unsubscribes and complaints. If they rise, something is wrong: an old list, too much frequency or content that isn't useful.
- Opens, only as a rough signal.
The legal side in 6 lines
The Spanish law that applies is the LSSI (Ley de Servicios de la Sociedad de la Información, Spain's e-commerce law, article 21) together with the RGPD (the GDPR) when you process personal data. In short:
- You need the recipient's prior consent, or an existing relationship with them (they are a customer) and the product or service must be similar.
- Every message must identify you as the sender and say clearly that it is advertising.
- Every message must offer a simple, free way to unsubscribe, and you must honour it.
- Keep proof of consent: date, source and the text accepted.
- Don't buy lists or use data from another source without a legal basis.
- Explain who processes the data, for what purpose and how to exercise rights, in the privacy policy.
This is a general guide, not legal advice. For specific cases, consult whoever handles your data protection.
How to start for free
- Start with a list of your own. A spreadsheet with name, email, and the date and source of consent. Ask for permission at the counter, on the booking form or on the website, with an unticked box.
- Choose a simple tool. There are options with a free plan for small lists; check the limits and where the data is stored. Compare them in email marketing for small businesses.
- Send 1 email a month with a single message and a single button. You rarely need more.
- Measure replies and appointments and adjust the subject line, the day and the content.
- Make unsubscribing one click. It is mandatory and it also builds trust.
If you already have customers and want someone to set it up, my email marketing service starts at €200/month; before hiring anyone, compare it with what an email marketing agency does for small businesses (in Spanish).
Frequently asked questions about mailing
Is it legal to email my customers?
Yes, if the conditions are met: either they have given you their consent, or they are your customers, what you offer is similar to what they bought, and you gave them the option to object when you collected their data and in every message. Always with identification and a simple way to unsubscribe.
How often should I send a mailing?
For a local business, once a month is enough. If you don't have a clear reason (season, promotion, reminder), don't send. It is better to send less often and with something useful.
Which mailing tool should I use?
One you can keep up with. Those with a free plan are fine for getting started with small lists. Choose by contact limit, whether it handles unsubscribes automatically and where the data is stored.
What is a good open rate?
Today opens are inflated by the privacy protection in some email apps, so they are not a good indicator. Measure replies, clicks, appointments or sales, which are what matter.
Mailing or WhatsApp?
It depends on permission and on your customers' habits. WhatsApp works well for reminders and conversations, and it also requires consent for advertising. Email suits longer messages and keeping a record. For a local business, using both with permission is often the best option.
In short
Mailing is sending a commercial message to a list, and for a local business it is mainly useful for talking again to customers you already have: reminders, seasonal offers, reviews. Start with a list built on permission, a simple tool and one send a month; measure replies, not opens; and take care of the legal side. If you want help setting it up, get in touch.
