Email Marketing: What to Include, How to Write One, and Common Mistakes

Email marketing remains one of the most direct ways to reach your customers and drive sales. But sending emails without a plan is just noise. This guide covers exactly what to include in your campaigns, how to write emails that get opened and clicked, and the common mistakes that kill your results.

What to Include in Every Email Campaign

Every professional email you send should have five core elements. Miss one, and your message loses impact.

A click-worthy subject line. This is your first impression. Keep it between 6-10 words for the highest open rates. Avoid spam triggers like “urgent,” “free,” or “win” — those send you straight to the junk folder. Personalize with the recipient’s name when possible; it can boost opens by up to 26%.

Optimized preheader text. That short snippet after the subject line is prime real estate. Don’t repeat the subject line. Use it to add a second hook or a clear call to action. Keep it under 140 characters so it doesn’t get cut off on mobile.

A single, clear message. One email, one goal. Trying to pitch a product, share a blog post, and announce an event in the same email confuses readers. Decide your primary objective — drive a sale, get a download, or nurture a lead — and build the email around that.

A strong visual and structure. Your header image should reflect your brand and be consistent across campaigns. After that, structure your email for scanning. Use short paragraphs, bullet points, and bold headers. People don’t read emails word-for-word; they scan for what matters to them.

A compelling call to action (CTA). Tell the reader exactly what to do next. Use action verbs like “Get Your Discount,” “Download the Guide,” or “Claim Your Spot.” One CTA per email is best. Too many choices lead to no choice at all.

How to Write an Email That Gets Results

Start with your goal. Before you write a single word, ask: “What do I want the reader to do?” That answer shapes everything — subject line, body copy, and CTA.

Write your subject line second, after you know your message. Test two versions with A/B testing if your platform supports it. For example, test a benefit-driven line (“Save 20% on Your Next Order”) against an emotional one (“Don’t Miss Out on Your Favorite Items”).

Your opening paragraph should hook the reader. Don’t waste space on pleasantries like “We hope this email finds you well.” Get to the value immediately. Example: “Your free trial ends in 48 hours. Here’s how to extend it.”

Keep your body copy tight. Use short sentences. Break up text with white space. If you’re promoting a product, highlight one key benefit and show a clear offer. If you’re nurturing, share a useful tip or a quick win the reader can apply right now.

End with a clear, single CTA button. Make it stand out visually. Place it near the top of the email and repeat it at the bottom. Track your click-through rate to see what works.

Common Mistakes That Hurt Your Campaigns

Buying an email list. This is the fastest way to ruin your sender reputation. Purchased lists are full of people who never opted in, which leads to spam complaints and low engagement. Build your list organically with opt-in forms on your website, social media, and at checkout.

Sending without a strategy. Random emails with no consistent schedule or goal confuse subscribers. Define your campaign objectives first: lead generation, customer retention, product promotion, or content sharing. Then map out a content calendar.

Ignoring mobile optimization. Over 60% of emails are opened on mobile devices. If your email doesn’t render properly on a phone, you lose that reader. Use a responsive template, keep your subject line short, and make your CTA button big enough to tap.

Not segmenting your audience. Sending the same email to everyone is lazy. Segment by behavior, demographics, or past purchases. Personalized emails can improve click-through rates by up to 50%. Even simple segmentation — new subscribers vs. repeat buyers — makes a difference.

Overloading the email with images. Some email clients block images by default. If your entire message is an image, your reader sees nothing. Use images to support your copy, not replace it. Always include alt text for key images.

Forgetting to test and track. Email marketing gives you more data than almost any other channel. Watch your open rates, click-through rates, and conversion rates. Run A/B tests on subject lines and CTAs. If something isn’t working, change it.