Email Marketing / Newsletter

What is email marketing?

Email marketing is the use of email as a marketing channel to send targeted messages to a list of qualified contacts. It covers newsletters (regular, useful content), promotional emails (offers, sales), transactional emails (order confirmation, delivery tracking) and automated sequences (onboarding, abandoned basket recovery).

Email marketing has the best ROI in digital marketing: 36€ for every euro spent on average (DMA, 2025). Despite the rise of social media and instant messaging, email remains the most reliable way to reach your audience: 4.5 billion people use email in 2026, and 99% check their inbox every day.

Types of marketing email

The newsletter is an email sent on a regular schedule, weekly or monthly, with content of real value: industry news, advice, case studies, new releases. The aim is to keep the relationship alive and stay top of mind. The best newsletters see open rates of 40-60% and click rates of 5-10%.

Promotional emails announce offers, sales or launches. Use them sparingly, 2 or 3 a month at most, or you will wear your audience out. Subject lines with a sense of urgency ("Last day", "Only 3 places left") lift open rates by 22%.

Automated sequences are emails triggered by specific actions. The welcome sequence (3 to 5 emails after sign-up) has an average open rate of 86%. Abandoned basket recovery wins back 10 to 15% of lost baskets. Lead nurturing educates and qualifies prospects over 2 to 4 weeks before the sale.

Email marketing best practice

The subject line decides whether your email is opened or ignored. It should be 50 characters at most and either spark curiosity or state a clear benefit. Emojis in the subject line lift open rates by 15% but should be used in moderation. Personalisation ("First name, your quote is ready") lifts open rates by 26%.

The content should be scannable: headings, subheadings, bullet points, and a single main CTA per email. The ideal text to image ratio is 60/40. Emails that are all visual (100% image) often land in spam.

Segmentation is the key to performance. Sending the same email to your whole list does not work. Segment by behaviour (buyers versus prospects), by interest (products viewed) and by engagement (active versus dormant). Segmented campaigns generate 760% more revenue than unsegmented ones.

Deliverability: the invisible enemy

Deliverability is the percentage of emails that actually land in the inbox rather than in spam. On average, 15% of marketing emails end up in spam. To maximise deliverability: send from an authenticated domain (SPF, DKIM, DMARC), keep your list clean (remove bounces and dormant contacts), and avoid spam trigger words ("free", "click here", too many capitals).

The main email marketing tools are Resend (a developer API, the one we use at ConvertiLab), Brevo (formerly Sendinblue, a French solution), Mailchimp (the best known) and ConvertKit (ideal for content creators).

GDPR compliance

In Europe, sending marketing emails requires the recipient's explicit consent (opt-in). Every email must contain a working unsubscribe link. You have to keep proof of consent. GDPR fines can reach 20 million euros or 4% of turnover.

How to build a quality email list

An email list is built patiently, never bought. The basic principle: offer value in exchange for an address. The lead magnet (ebook, checklist, template, discount, mini course) is the most effective engine. Then place sign-up points in the right spots: an exit intent popup, a sticky bar at the top of the site, a box at the end of blog articles, and of course the contact form.

A concrete example: a consultant who offers a downloadable PDF guide in exchange for an email address can convert 3 to 5% of visitors into subscribers. With 2,000 visitors a month, that is 60 to 100 new qualified contacts a month, which makes a list of more than 1,000 subscribers in a year, with no advertising budget. A list of 1,000 genuinely interested contacts is worth infinitely more than 10,000 bought addresses, which destroy your deliverability and expose you to GDPR penalties.

Common email marketing mistakes

The most widespread mistakes wreck entire campaigns:

- Buying or renting lists, which ruins deliverability and breaches the GDPR. - Sending too often and triggering a wave of unsubscribes and spam complaints. - Neglecting the mobile version, when more than half of all emails are opened on a smartphone. - Writing a bland or misleading subject line, which either sinks your open rate or destroys trust. - Forgetting to clean dormant addresses from your list, which damages your sender reputation. - Piling up CTAs in one email, which dilutes the action you want.

Checklist before sending a campaign

Before each send, run through these points:

- Subject line tested, ideally with an A/B test, and under 50 characters. - First name personalisation checked on a sample. - One main CTA, clearly visible. - Rendering checked on mobile and in the main email clients. - Unsubscribe link present and working. - SPF, DKIM and DMARC authentication active on the sending domain. - A targeted segment rather than the whole list. - Send scheduled for a time that suits your audience.

Email marketing trends in 2026

In 2026, email marketing is becoming more sophisticated. Behaviour triggered sequences (automated journeys based on the pages visited or the emails clicked) comfortably outperform mass sends. Hyper-personalisation, fed by first party data, makes it possible to adapt content and offer to each profile. Finally, as privacy protection tightens (Apple Mail Privacy Protection inflates open rates, for instance), the benchmark metrics are shifting towards click rate and revenue generated, which are more reliable than open rate alone.

Email is still the only channel where you genuinely own your audience, independently of any algorithm. Neglecting it means leaving money on the table.

At ConvertiLab, we build optimised email capture forms and automated sequences, connected to tools such as Resend and Brevo, to turn your visitors into prospects and then into loyal customers.