Opt-in email marketing: The complete guide [2026]

Opt-in email marketing is one of the most reliable ways to grow revenue online. According to recent Omnisend studies, automated emails now drive 37% of all email-generated sales. Those automations only work on subscribers who said yes.

The problem most ecommerce brands run into isn’t getting people on a list. It’s getting the right people — subscribers who consistently engage and purchase.

This guide covers everything you need to run successful opt-in email marketing for your store. You’ll find real opt-in email examples, ready-to-use opt-in templates, and proven best practices. You’ll also find clear compliance guidance for GDPR and CAN-SPAM.

Whether you’re starting from zero or tightening up what you already have, this guide gives you a practical framework to build a compliant, high-performing email list.

What is opt-in email marketing?

Consent is what separates a high-performing email list from one that gets ignored or flagged as spam.

So what does email opt-in mean in practice?

It simply means you have permission. And with that permission comes better open rates, stronger engagement, and fewer deliverability issues. Your email deliverability depends heavily on sending to people who actually want your emails.

There are three types of opt-in email marketing you need to know:

Single opt-in

Single opt-in is the most common method. A visitor enters their email address and is immediately added to your list. It’s fast and removes friction, but it also means fake addresses or typos can slip through. Your list grows faster, but may be less clean. Single opt-in is the entry point for most opt-in email marketing strategies.

Double opt-in

What is double opt-in email marketing? It’s when a subscriber confirms their signup through a second verification step before being added to your list. This extra step filters out bad addresses and bots. The result is a smaller but more engaged opt-in email list. Double opt-in is widely considered the gold standard in opt-in email marketing.

Implied opt-in

Implied opt-in happens when a business relationship already exists. For example, a customer who just bought from your store has an implied connection. But that doesn’t mean they’ve agreed to receive your marketing emails. Implied opt-in doesn’t meet the consent bar most opt-in email marketing regulations require, especially under GDPR.

Omnisend supports both single and double opt-in workflows, so you can choose the setup that fits your list-building goals.

Opt-in email examples

Seeing real email opt-in examples is far more useful than reading about them. Below are three opt-in email examples that show exactly what good consent-based emails look like and what you can take from each one.

Double opt-in email example

Republic’s double opt-in email is clean and to the point. The subject line “Welcome to Republic” is warm without being vague.

The consent copy is one sentence, the CTA says “Verify your email,” and there’s nothing else fighting for attention.

What you can take from this:

• Keep your consent copy short. Subscribers already know why they’re getting this email.
• Use an action-focused CTA. “Verify your email” is clearer than “Click here” or “Confirm.”
• Cut the design clutter. A minimal layout keeps attention on the one action you need them to take.

Newsletter opt-in email example

Olio’s newsletter opt-in confirmation works well for a few reasons. Among newsletter opt-in examples, this one stands out because of a small but smart addition.

A disclaimer below the CTA states that subscribers won’t be added unless they click. That one line builds trust and filters out accidental signups.

What you can take from this:

• Add a disclaimer below your CTA. It reassures genuine subscribers and weeds out accidental signups.
• Match your email design to your brand. Olio’s gradient header is instantly recognizable.
• Write your CTA in the first person. “Yes, I want to subscribe” feels like a choice, not a command.

GDPR opt-in email example

Archant’s re-engagement email is a strong GDPR double opt-in email example. Instead of assuming consent, it asked existing subscribers to update their preferences.

The CTA goes to a preference center rather than a plain unsubscribe page, and the tone stays friendly throughout.

What you can take from this:

• If you’ve never collected explicit consent, a re-permission campaign is the right first step. It’s a clean way to refresh your list and stay GDPR-compliant.
• Send people to a preference center, not just an unsubscribe link. It gives subscribers more control and reduces list churn.
• Keep the tone warm. A compliance-related email doesn’t have to feel cold or corporate.

Omnisend’s email builder includes pre-built opt-in confirmation email templates you can customize and launch quickly.

Opt-in email templates

Good email opt-in wording examples are hard to find. Most guides tell you what to write, but never show you.

Below are ready-to-use opt-in templates across three areas — your signup form copy, your confirmation email subject lines, and your re-engagement emails.

Opt-in form template copy

Your opt-in form is usually the first thing a subscriber sees. Getting the wording right makes a real difference to your signup rate. Here are three opt-in form template variations to plug straight into your store.

Discount-led form copy

This works well when you want fast list growth and have enough margin to offer a discount.

Value-led form copy

Best for stores with a strong loyalty angle.

Gamified form copy

Works well with Omnisend’s Wheel of Fortune signup form. It typically attracts higher engagement because visitors are curious about what they’ll win.

Here’s what that looks like inside Omnisend’s form builder:

Subject line templates for opt-in confirmation emails

Your confirmation email is the first real touchpoint after signup. These opt-in page template subject lines are built around two proven open rate drivers, including personalization and curiosity:

• “Please confirm your subscription!”
• “Hi [First Name], welcome to [Brand] — one step left”
• “Your [X]% off code is waiting — confirm your email to grab it”
• “You’re almost in — click to confirm your spot”
• “Still want to hear from us? Confirm here”

Re-opt-in email example

Re-engagement is one of the most overlooked areas of opt-in email marketing. A re-opt-in email goes to subscribers who’ve gone quiet for a long period. Here’s a simple template to adopt:

This template covers the three essentials:

• A clear reason to re-engage
• One CTA
• An easy way out

Removing inactive subscribers also keeps your email deliverability strong.

Omnisend’s drag-and-drop form builder and email template library include pre-built opt-in form templates for ecommerce — no design skills needed.

Understanding implied and explicit email opt-in

When building an email list, it helps to first understand what email opt-in is and how consent is obtained in practice. Getting this wrong can undermine your entire opt-in email marketing strategy.

Both implied and explicit opt-in involve user permission, but they differ in how that consent is collected.

Implied opt-in

An opt-in email relationship is implied when a business already has an existing relationship with a customer who hasn’t directly subscribed to marketing emails.

While implied opt-in allows you to send transactional or service-related emails, it doesn’t give you permission to send promotional content.

Implied opt-in happens when:

• A customer provides their email during a purchase: They gave you their email to complete a transaction — that’s not the same as agreeing to receive your marketing emails.
• A user downloads a resource or signs up for a free trial: Without explicitly checking a box to receive marketing emails, their email address shouldn’t go into your promotional list.

Since GDPR requires explicit consent for marketing emails, you generally can’t rely on implied opt-in alone.

Explicit opt-in

Explicit email opt-in means the subscriber has actively and clearly agreed to receive marketing emails from you. It’s the standard that ensures GDPR compliance and tends to produce a more engaged list with fewer spam complaints.

Explicit opt-in happens when:

• A subscriber fills out a signup form and checks a consent box: The checkbox was unchecked by default, and they actively ticked it. The consent language made the purpose clear.
• The subscriber then confirms through a double opt-in process: They received a confirmation email and clicked the link. This adds a second layer of verified consent.

For ethical and effective email marketing, an explicit opt-in is the standard to work toward across all your touchpoints. Explicit opt-in is the foundation of any serious opt-in email marketing program.

Here’s what a compliant explicit opt-in checkbox looks like on a checkout page:

Omnisend defaults to unchecked opt-in boxes on all signup forms, so your consent collection stays compliant without any manual setup.

When is opt-in necessary for email marketing?

Opt-in email marketing is legally required in most major markets. From a legal standpoint, regulations such as the GDPR and the CAN-SPAM Act require businesses to obtain email consent before sending marketing emails.

GDPR applies to any business targeting EU customers. It requires clear, explicit consent before you send marketing emails. Violating it can cost you up to €20 million or four percent of your global annual turnover — whichever is higher.

For newsletters specifically, GDPR makes double opt-in effectively mandatory in several EU countries, a concept known in German-speaking markets as “newsletter double opt-in pflicht.”

In the US, the CAN-SPAM Act requires a working opt-out option in every commercial email. You must honor opt-out requests within 10 business days. Non-compliance can result in fines of up to $53,088 per violating email.

Beyond legal compliance, opt-in is also necessary in these situations:

• Growing an email list: Subscribers must willingly sign up through forms, popups, or checkboxes.
• Sending promotional campaigns: You should only email users who have opted in to receive offers, newsletters, or updates.
• Avoiding spam filters: ISPs prioritize senders with verified, engaged subscribers. A permission-based list protects your sender reputation.

Looking at GDPR opt-in email examples, you’ll see that brands that get consent upfront have fewer deliverability problems and better long-term engagement.

Omnisend includes built-in GDPR compliance features across all signup forms, including configurable consent language and unchecked opt-in boxes by default.

Acceptable forms of email opt-in

Knowing how to build an opt-in email list the right way starts with understanding which collection methods actually count as consent. These are the five widely accepted approaches under both GDPR and CAN-SPAM.

• Signup forms: Visitors enter their email on a website or landing page. The purpose of the form must be clearly stated.
• Checkboxes on checkout pages: An unchecked box during checkout lets customers opt-in without feeling pressured. The box must be unchecked by default to count as valid consent.
• Popups and slide-ins: These capture visitor interest by offering exclusive offers in exchange for an email address. They work well when timed correctly and are easy to dismiss.
• Lead magnets: Free resources like ebooks or discount codes encourage people to subscribe while offering something useful in return. The signup intent must be clear.
• Double opt-in confirmation: The subscriber receives a confirmation email and must click to verify. This produces a cleaner, more engaged opt-in email list.

Here’s how each of these looks inside Omnisend’s form builder:

Omnisend’s pre-built popup templates and native checkout opt-in integrations for Shopify and WooCommerce make it straightforward to run opt-in email marketing the right way from day one.

Unacceptable forms of email opt-in

Knowing how to get opt-in email lists the right way also means knowing which methods to avoid entirely. These practices put your entire opt-in email marketing program at risk.

Here are five email opt-in practices to avoid:

• Pre-checked boxes: A checkbox that’s already ticked assumes consent rather than asking for it. This is one of the most common GDPR violations and one of the easiest to fix:

• Scraped or purchased email lists: Some services let you buy opt-in email lists of people who have agreed to receive marketing. But those people never opted in to hear from you in particular. A bought opt-in list is not a real email opt-in list and damages your sender reputation.
• Forced opt-in: Requiring someone to subscribe to access a product or service isn’t genuine consent. This practice can violate GDPR and is generally considered coercive.
• Adding customers without permission: A customer who bought from your store gave you their email for a transaction, like an order confirmation email. That doesn’t automatically give you permission to send them marketing emails.
• Burying consent in terms and conditions: Hiding email marketing consent inside lengthy terms and conditions doesn’t meet GDPR’s standard for informed consent. Subscribers must know clearly what they’re agreeing to.

Common scenarios requiring opt-in

Knowing when opt-in consent is required helps you stay compliant and build the best signup form for high conversions. Here are seven common scenarios where explicit opt-in is a must:

• Newsletters and content updates: Subscribers must explicitly opt-in to receive your newsletter or blog updates. For Shopify stores, the double-opt-in settings for the Shopify newsletter help record this consent properly. Sending an opt-in newsletter without explicit consent puts you at risk under GDPR.
• Promotional emails: Customers must give clear consent before receiving discount codes, product launches, or seasonal offers.
• Abandoned cart emails: A customer who abandoned their cart must have opted in before you send promotional follow-ups.
• Event invitations and webinars: Attendees must opt-in to receive follow-up emails after events or webinars.
• Customer feedback and surveys: Only opted-in subscribers should receive review requests or survey invitations.
• Loyalty and rewards programs: Users must actively sign up and agree to receive loyalty program updates.
• Re-engagement campaigns: Some subscribers go quiet over time. Before sending winback emails, confirm they still want to hear from you. Those who don’t respond should be removed. The re-opt-in email templates earlier in this guide are a good starting point.

Omnisend’s ecommerce automations — from abandoned cart to loyalty re-engagement — are built around opt-in consent, so every email reaches people who actually want it.

Opt-in email marketing best practices

Good email opt-in marketing starts with building a list of people who actually want to hear from you. These seven practices help you do that well.

Offer value-driven signups

People don’t hand over their email for nothing. Give them a reason — a discount, early access, exclusive content, or a free resource.

To’ak Chocolate, an Omnisend customer, attributes nearly 39.4% of its email revenue to automated campaigns that start the moment someone subscribes. That first offer sets the tone for the whole relationship. This is opt-in email marketing at its most effective.

Use clear and transparent consent

Knowing how to write an opt-in email with clear consent language makes a real difference to your signup rate. Be specific in your form copy — “Get weekly deals and new arrival alerts” is better than “Sign up for updates.”

Implement segmentation from the start

Knowing how to build an opt-in email list is one thing. Knowing how to organize it is another. Segment subscribers from the start based on how they signed up, what they browsed, or where they’re located.

Good opt-in email marketing uses segmentation to make every message feel relevant. Pair your segments with email automation to send the right message to the right person without doing it manually every time.

Leverage personalization

Personalized emails consistently outperform generic ones. Use your subscriber’s name, reference products they’ve browsed, and tailor offers to their purchase history. Personalization is what separates basic opt-in email marketing from high-performing campaigns.

Use a double opt-in process

Double opt-in filters out fake addresses and keeps your list clean. A subscriber’s engagement is at its peak the moment they confirm their signup, so trigger an automated email campaign immediately. This is one of the simplest ways to strengthen your opt-in email marketing results.

Make it easy to opt out

A clear unsubscribe link in every email is both a legal requirement and good practice. Subscribers who can’t easily leave tend to mark emails as spam instead. That damages your sender reputation far more than a clean unsubscribe ever would.

Optimize for mobile users

More than half of all emails are opened on mobile devices. Your signup forms and emails need to work just as well on a phone as on a desktop. Keep forms short, use large tap targets, and test every email on mobile before sending. Mobile optimization is a non-negotiable part of modern opt-in email marketing.

Here’s what a high-converting opt-in form covers in practice:

Brands using Omnisend’s opt-in email marketing services report strong returns. Omnisend customers average $79 for every $1 spent — one of the highest ROIs in email marketing.

How to create high-converting opt-in forms

Your opt-in form is often the first impression a visitor gets of your brand. A well-designed form can be the difference between a bounce and a new subscriber. Here’s how to get it right.

1. Place forms strategically

Position opt-in forms where visitors are most likely to engage. Good placement includes:

• Website headers or footers for easy access
• Exit-intent popups to catch visitors before they leave
• Blog posts and landing pages where visitors are actively reading

Hypebae is a strong newsletter opt-in example. It placed its signup popup on the landing page, making sure visitors see the subscription offer right away. This is a common approach among newsletter opt-in examples that prioritize visibility without being intrusive:

2. Keep the form simple

The fewer fields you ask for, the higher your conversion rate. For most ecommerce stores, an email address is all you need at signup. You can collect more information later through preference centers or post-purchase flows. Here’s a great example of a mobile opt-in form:

A good opt-in form template keeps the design clean and the ask small. The easier it is to sign up, the more people will.

3. Write a compelling call to action

Generic CTAs like “Submit” or “Sign up” underperform. Use action-oriented, benefit-focused copy instead. “Get my 10% off” outperforms “Subscribe” because it tells the subscriber exactly what they’re getting.

Glossier does this well. Its “Claim 15% off” CTA is direct and benefit-led — the subscriber knows what happens the moment they click:

4. Use eye-catching design

Your form needs to stand out without clashing with your brand. Use contrasting colors for the CTA button, keep the layout uncluttered, and make sure the form is easy to read at a glance. A form that blends into the page gets ignored. Here’s a great example:

5. Build trust with social proof

Showing that others have already subscribed reduces hesitation. Subscriber counts, trust badges, or brand logos all work well here.

Trello uses this approach on its homepage — it references its “community of millions” and displays logos of well-known companies that use its product. That kind of social proof makes new visitors more comfortable taking action:

6. Leverage A/B testing

Never assume your first version is the best version. The average email opt-in rate is around 1.95%. But top-performing stores consistently beat that with the right combination of opt-in form elements.

Test different headlines, CTA copy, form placement, and incentive types. Small changes can lead to meaningful lifts in conversion rate. Testing is how you continuously improve your opt-in email marketing signup rates.

Omnisend’s signup form builder lets you design, test, and publish high-converting opt-in forms. It covers everything from exit-intent popups to embedded forms, with built-in A/B testing and real-time analytics. Here’s a look at Omnisend’s A/B testing dashboard:

How to handle opt-out requests and maintain compliance

Handling opt-outs correctly is just as important as getting opt-ins right in opt-in email marketing. Making it easy for subscribers to opt out protects your brand reputation and keeps you on the right side of the law. Here’s how to handle opt-outs the right way:

• Provide a clear unsubscribe link: Every email should include a visible unsubscribe option. It should take no more than one or two clicks to complete.
• Honor opt-out requests immediately: Under the CAN-SPAM Act, you must process opt-out requests within 10 business days. Delays put you at legal risk and damage subscriber trust.
• Avoid guilt-tripping users: Don’t use manipulative language to discourage unsubscribes. A respectful opt-out experience leaves a better impression.
• Offer email preferences options: A preference center lets subscribers adjust frequency or content type instead of unsubscribing completely. Some people want fewer emails, not none.
• Confirm the opt-out, but don’t send follow-ups: A confirmation page is helpful. But sending a follow-up after someone unsubscribes may put you in violation of regulations.

Omnisend’s opt-in email marketing services automatically process unsubscribe requests in real time. Compliance with CAN-SPAM, GDPR, and CASL is handled at the platform level, so you never have to track opt-outs manually.

Conclusion

Here’s a quick summary of the most important things to know about opt-in email marketing.

FAQ