Email marketing best practices

A small list of people who want your email beats a large one that does not. Every address you add without consent costs you opens, complaints and sender reputation.

• Use double opt-in

  Ask new subscribers to confirm their address. It keeps typos and fake signups off your list and cuts spam complaints.

• Say what they will get

  “Get weekly tips on onboarding” beats “Subscribe to our newsletter”. State the topic and how often.

• Put forms where people are

  Your website, blog, checkout page, social profiles and in-person events.

• Offer an incentive

  An ebook, discount, template or exclusive content gives people a reason to sign up.

• Keep forms short

  Ask for an email address, and a name only if you will use it.

• Buy lists

  Purchased addresses never opted in. Expect spam complaints, bounces and a damaged reputation.

• Pre-check the box

  Subscribers must opt in themselves. Pre-checked boxes break GDPR.

• Hide the terms

  Be clear about what you send and how often before someone signs up.

The subject line decides whether an email gets opened. Keep it under 50 characters and say what is inside. More in the open rate guide.

• Personalize beyond the first name

  Use purchase history, browsing activity and stated preferences. Personalized emails deliver 6x higher transaction rates than generic blasts.

• One email, one goal

  Give each email a single call to action. Several compete with each other and lower conversions.

• Write for skimmers

  Paragraphs of two or three sentences, bullet points, clear subheadings, white space, and bold for the key point.

• Make the CTA specific

  “Start your 14-day free trial”, not “Get started”. “Download the guide”, not “Click here”. Use a button in a contrasting color, and add urgency only when it is real. See the click-through rate guide.

• Give something every time

  An insight, a fix, exclusive content. Emails that only promote get unsubscribed.

• Mobile first

  Over 60% of emails are opened on a phone. Use responsive templates and tap targets of at least 44×44px.

• Light images with alt text

  Compress images and write alt text, since many clients block them. Aim for 60/40 text to image, and never send image-only emails.

• Consistent branding

  Same colors, fonts, logo and voice every time, so readers recognize you. Build from templates.

• Accessible

  Contrast of 4.5:1 or more, body text of 14px or larger, descriptive link text and semantic HTML.

• Tested across clients

  Gmail, Outlook and Apple Mail render the same email differently. Check them all before the full send.

These are starting points. Your audience may behave differently, so A/B test send times and keep what the data supports.

Watch unsubscribes when you send more often. If they spike, you have gone past what your list wants.

Segmented campaigns get 30% more opens and 50% more clicks than sending the same email to everyone. Group contacts by what you know about them, then write for each group.

• Demographics

  Age, location, job title, company size.

• Behavior

  Purchases, browsing activity, email engagement.

• Lifecycle stage

  New subscriber, active customer, churned user.

• Engagement

  Highly engaged against inactive subscribers.

• Preferences

  Product interests, topics, preferred frequency.

• Purchase recency

  Recent buyers against lapsed customers.

Campaigns that only work with segments:

• A welcome series for new subscribers
• Re-engagement for inactive users, and win-back for churned customers
• Product recommendations based on past purchases
• Location-specific offers and events
• VIP campaigns for high-value customers

• Change one variable

  Otherwise you cannot tell what made the difference.

• Use enough recipients

  At least 1,000 per variant for a significant result.

• Run it long enough

  Let the test cover timing differences across the day.

• Split at random

  Not by hand-picked segments.

• Ship the winner

  Then test the next variable.

Marketing email is regulated, and breaking the rules means fines and lost trust. The two laws most senders deal with:

Watch engagement to judge content, and health metrics to catch problems before inboxes do.

And the ones you calculate yourself:

• Click-to-open rate

  Clicks divided by opens.

• Conversion rate

  Goal completions divided by delivered.

• List growth rate

  New subscribers against unsubscribes.

• ROI

  Revenue generated divided by cost.

• Revenue per email

  Total revenue divided by emails sent.

• Customer lifetime value

  The long-term value of a subscriber.

• Cost per acquisition

  What it costs to win a customer.

If delivery or inbox placement slips, start with the deliverability guide, and run new campaigns through the spam checker before you send.