Email marketing: the guide

What is email marketing?

Email marketing, also called emailing, refers to sending electronic messages to a list of recipients. The sending goes through specialised software, for a commercial or relationship purpose. It targets people who already have a link with the company: customers, subscribers, registered prospects.

It is a channel the company owns. Its reach does not depend on a third-party algorithm, as it does on social networks or in advertising. It depends on the quality of the list and on the sender’s reputation with mailbox providers.

Type of email	Trigger	Objective
Newsletter	Editorial calendar (weekly, monthly)	Keep in touch, establish expertise
Promotional campaign	Offer, launch, key sales period	Sell, bring people into the store
Transactional email	User action (order, password)	Inform about a service provided
Automated sequence	Behaviour or date (sign-up, cart, birthday)	Guide, follow up, convert

Mailing, emailing, newsletter: what is the difference?

In everyday use, many people say “mailing” when they mean emails, and the two terms get mixed up. “Emailing” removes the ambiguity. A newsletter, on the other hand, is not a synonym. It is one type of email marketing among others, sent on a fixed schedule to subscribers. A promotional campaign or an automated sequence are also email marketing without being newsletters.

What does the law say about email marketing?

In France, sending commercial emails falls under the GDPR and Article L34-5 of the French Postal and Electronic Communications Code (Code des postes et des communications électroniques). The CNIL (the French data protection authority) summarises the rules in its fact sheet on email marketing (in French).

Recipient	Rule	Exception or nuance
Consumer (B2C)	Prior consent: unticked checkbox, free and informed choice	Existing customer, for similar products or services, if they were able to object at the time of collection
Professional (B2B)	Sending possible without prior consent, to the work address	The message must relate to their profession; simple, free right to object
Everyone	Identify the sender and offer a simple way to unsubscribe in every message	None

Creating a customer account does not count as a purchase. The CNIL states that it is not enough to invoke the “customer” exception. Keep proof of consent: date, form, text displayed. Article 7 of the GDPR requires the sender to be able to demonstrate it.

Tracking pixels: the 2026 CNIL recommendation

A tracking pixel is an invisible image inserted in the email. When it loads, it signals an open. The CNIL treats it as a tracker within the meaning of Article 82 of the French Data Protection Act (loi Informatique et Libertés). Its recommendation was published in the Journal officiel, France’s official gazette, on April 14, 2026. It requires consent for pixels used to measure marketing performance, to personalise or to analyse behaviour. The CNIL questions and answers (in French) of July 22, 2026 clarify how it applies.

• Exempt from consent: individual deliverability measurement, used to identify inactive contacts in order to reduce or stop sending. Security pixels in authentication emails are also exempt.
• Addresses collected before April 14, 2026: the CNIL allowed until July 14, 2026 to inform recipients and let them object.
• Refusing must be as easy as accepting. The choice is remembered so that it is not asked again with every send.

How do you build and segment your email list?

A quality list is worth more than a large one. Every inactive or poorly collected address damages your sending reputation. Deliverability then drops for all the other contacts.

1. Collect: forms on the website, at the checkout or at an event, with a clear promise (what, how often).
2. Confirm: double opt-in (a confirmation email) is not required by law. It does, however, filter out fake addresses and typing errors.
3. Qualify: a few useful fields (interests, customer or prospect status), not a twenty-question form.
4. Segment: by status, by purchase history, by stated interest, by level of engagement.
5. Clean: remove bouncing addresses, send a follow-up and then set aside long-term inactive contacts.

As for retention, a prospect’s data can be kept for three years after collection or their last contact. This is the rule in the CNIL reference framework on customer management (questions and answers of January 28, 2022, in French). Our CRM and customer loyalty pillar page details this point, along with segmentation and personalisation.

How do you write an email that gets read?

An email is read in a few seconds, often on mobile. Its construction follows the reading order: sender, subject line, preheader, then content.

• Sender: a recognisable, stable name that does not change from one send to the next.
• Subject line: short, concrete, true to the content. A misleading subject line drives up complaints.
• Preheader: the line shown after the subject. It completes the promise instead of repeating it.
• One message, one action: a single main call to action, visible without scrolling.
• Readability: real text rather than images, sufficient contrast, alt text on images, a plain-text version.

The rules of web writing apply: short sentences, benefit before feature, proof rather than adjectives. The tone follows your brand identity. For the landing page, see our CRO pillar page.

Newsletter: frequency and editorial line

The newsletter is the email most prone to fatigue, because nothing triggers it except the calendar. It holds up if each issue brings something the subscriber cannot find elsewhere. For example: an analysis, a curated selection with commentary, a figure explained.

• Announce the frequency at sign-up and stick to it: a regular pace is better than a heavy one.
• Keep a fixed structure (one main topic, two or three short items) so the reader knows where to look.
• Let subscribers choose their frequency or topics, rather than the sole choice of staying or leaving.
• Watch unsubscribes and complaints after each issue. A rise signals a topic or a pace that is off.

A B2B newsletter often serves as the entry point to nurturing. It keeps in touch with prospects who are not yet ready to buy.

Deliverability: what do Gmail and Yahoo require?

Deliverability is an email’s ability to reach the inbox rather than the spam folder. Since 2024, the major mailbox providers have published precise requirements. For Gmail, they have applied since February 1, 2024 (Gmail sender guidelines).

Requirement	Gmail	Yahoo
SPF and DKIM	Both above 5,000 messages per day	Both
DMARC	At least p=none, with alignment	At least p=none, with alignment
One-click unsubscribe	Mandatory for bulk marketing sends	Mandatory; request processed within two days
Complaint rate	Below 0.3% (0.1% recommended)	Below 0.3%

Yahoo has applied similar rules since February 2024 (Yahoo best practices).

SPF, DKIM, DMARC: what are they for?

• SPF lists the servers authorised to send for your domain.
• DKIM signs each message to prove it has not been altered.
• DMARC tells mailbox providers what to do if SPF or DKIM fails, and sends you reports.

One-click unsubscribe relies on the IETF’s RFC 8058 standard, published in January 2017. A List-Unsubscribe-Post header lets the mailbox provider unsubscribe the user without them opening a page. Most email marketing software adds it automatically; check that it does.

Reputation is also built through use. A new domain or a new sending tool becomes known gradually. Start with your most engaged contacts, then increase volumes in stages. Monitor complaints in the mailbox providers’ tools, such as Google’s Postmaster Tools.

Marketing automation and lead nurturing

Marketing automation sends emails triggered by a behaviour or a date, with no manual action for each send. Lead nurturing is its most common B2B use. It guides a prospect with suitable content until they are ready to talk to a salesperson.

Sequence	Trigger	Typical content
Welcome	Sign-up	What the subscriber will receive, the most useful content, a first offer
Abandoned cart	Cart not completed	Product reminder, answers to objections (delivery, returns)
Post-purchase	Order delivered	Usage tips, review request, complementary products
B2B nurturing	Content download	A series of increasingly concrete content, then an offer to talk
Reactivation	Prolonged inactivity	Reminder of the value, choice of frequency, then removal from the list

A sequence is designed on paper before it is configured. It needs an objective, a trigger, three to five messages and an exit condition: purchase, meeting or unsubscribe. Without an exit condition, a customer who has just bought still receives the reminder for the product they now own.

Nurturing content often comes from content marketing: guides, case studies, webinars.

Which email marketing metrics should you track?

The open rate has lost its reliability. Apple’s “Protect Mail Activity” feature hides the IP address. It also downloads remote content in the background, when the message is received rather than when it is read (Mail User Guide, in French). The pixel then fires without the person having read the email. On top of this, there is now the consent required by the CNIL.

Metric	Calculation	What it tells you
Delivery rate	emails delivered ÷ emails sent	Is the list clean?
Click rate	unique clickers ÷ emails delivered	Did the message prompt an action?
Conversion rate	conversions ÷ emails delivered	Did the send produce a result?
Unsubscribe rate	unsubscribes ÷ emails delivered	Are the frequency or targeting wearing people out?
Complaint rate	spam reports ÷ emails delivered	Direct risk to deliverability

Measure conversions on the website with tagged links (UTM parameters) rather than in the email marketing software alone. The method is detailed in our web analytics pillar page.

How do you choose email marketing software?

There is no best email marketing software in absolute terms. The right tool depends on volume, the need for automation and the rest of your stack. Start by identifying the family of tools that matches your use.

Family of tools	For whom	Watch point
Simple email marketing tool	Newsletter and one-off campaigns, small or medium list	Automation often limited
Marketing automation platform	Sequences, scoring, B2B nurturing	Longer setup and learning curve
CRM or online store module	Team that wants a single customer database	Email features sometimes less extensive
Transactional sending service (API)	Emails triggered by a website or an app	Requires a developer; poorly suited to campaigns

Then compare the tools in the chosen family on these criteria rather than on a ranking:

• guided authentication of the sending domain (SPF, DKIM, DMARC), and native one-click unsubscribe;
• management of consent to the tracking pixel, contact by contact;
• segmentation and automation sequences at the level of complexity you need;
• connection to your CRM or your online store;
• data hosting and subprocessors, for your GDPR obligations;
• pricing model: by number of contacts or by number of sends.

Test the tool before migrating: import a segment, send yourself a real campaign and check the domain authentication. If the vendor offers a trial or a free plan, use it for this test.

For an overview of the channels and their role, see our digital strategy pillar page.