Email is the highest-ROI marketing channel available — consistently returning $36-42 for every dollar spent according to industry benchmarks. But those numbers assume the emails actually get opened, read, and acted on. Most don’t.
The average office worker receives over 120 emails per day. Yours is competing with newsletters from brands they love, messages from colleagues, order confirmations, and promotional emails from every other marketer trying the same playbook. Getting noticed requires copy that’s genuinely better than what’s around it.
Here’s how to write emails that earn opens, reads, and clicks.
The Subject Line Is Everything
The subject line is your most important copywriting asset in email. It determines whether your email gets opened or deleted without a second glance.
Rules for subject lines that work:
Be specific. “3 subject line formulas that doubled our open rate” beats “Tips for better email marketing.” Specificity creates believability and makes a concrete promise.
Trigger curiosity or self-interest. These are the two most reliable open motivators. Curiosity: “The counterintuitive reason your emails aren’t converting.” Self-interest: “How to write a sales email in under 15 minutes.”
Keep it short enough to display fully. Most email clients show around 60 characters of subject line on desktop and 30-40 on mobile. Front-load the important words.
Use “you” or speak directly to the reader. “How you can cut your editing time in half” feels more personal than “How writers can cut editing time in half.”
Test first-person occasionally. Subject lines written as if from a person — “Quick question for you” or “I wanted to share this before it closes” — often outperform brand-voice subjects because they feel human rather than automated.
Subject lines that consistently underperform:
- Vague teases (“You’re going to love this…”)
- All-caps words (triggers spam filters and feels aggressive)
- Too many exclamation points
- Misleading subject lines — even if they earn opens, the resulting distrust destroys long-term engagement
Don’t Neglect Preview Text
Preview text (also called preheader text) appears in the inbox view just after the subject line. Most marketers ignore it and let it default to “View this email in your browser” — which is a wasted opportunity.
Treat preview text as the second line of your subject line. Use it to:
- Complete a thought started in the subject line: Subject: “The email formula that generates $2k/week” / Preview: “From a writer with zero marketing background”
- Add context: Subject: “Your free template is inside” / Preview: “Saves 3 hours per week, no setup required”
- Create curiosity: Subject: “One word that kills email conversions” / Preview: “Most marketers use it in every CTA”
Aim for 85-100 characters of preview text. Keep it aligned with what’s actually in the email.
Email Structure That Keeps People Reading
Once you’ve earned the open, you have about 3-5 seconds to convince the reader to keep going. Email body copy should follow a structure that respects people’s time.
The opening line. Your first sentence is the most important line in the email body. It must do one thing: make the reader want to read the second line. Options:
- State the core benefit immediately
- Establish surprising context
- Ask a question the reader definitely has an answer to
- Open a story loop you’ll close later
Short paragraphs. Email readers scan before they read. Long blocks of text are skipped. Write paragraphs of 2-3 sentences maximum. Leave white space. Make the copy easy to dip in and out of.
One main message. Each email should be about one thing. Not “here’s our blog roundup plus a product update plus an event invite.” One message, one thread, one call to action. Every additional goal dilutes each one.
Build toward the CTA. Every paragraph should move the reader closer to the action you want them to take. Don’t meander. Don’t add information just because it’s interesting. If it doesn’t serve the purpose of the email, cut it.
Writing Calls to Action That Get Clicked
The CTA is where email copy either pays off or doesn’t. Most email CTAs are weak because they’re generic.
Compare:
- “Click here” — says nothing about value
- “Read the article” — marginally better, still generic
- “See how Sarah doubled her client list in 60 days” — specific, human, implies the reader will learn something valuable
CTA best practices:
- One primary CTA per email. Multiple options create indecision.
- Use a button or formatted link. Plain text links are easy to miss. Buttons increase click rates significantly.
- Repeat the CTA at the bottom. Long emails should have the CTA accessible at the start and repeated at the end.
- Make it specific to what happens next. “Start your free trial — takes 2 minutes” reduces friction by explaining what the reader is committing to.
Segmentation and Personalization
Sending the same email to your entire list is an increasingly poor strategy. Email platforms now make segmentation easy — and segmented campaigns generate significantly higher open rates and click-through rates.
Basic segmentation ideas:
- New subscribers (welcome sequence, education-focused)
- Active buyers (upsell, loyalty content)
- Lapsed subscribers (re-engagement sequences)
- Specific interests (different topic tags)
Personalization beyond first name also moves the needle. Referencing a subscriber’s behavior (“You downloaded our SEO guide last month, so you’ll appreciate this…”) creates a feeling of relevance that generic broadcast emails never achieve.
A/B Testing Email Copy
Email is the easiest marketing channel to test because the feedback loop is so fast. Within 24 hours of sending, you know how a subject line performed.
What to test (one element at a time):
- Subject line variations (different angles, lengths, emotional vs. logical)
- Preview text
- Opening sentence
- CTA copy
- CTA button color
- Email length (short vs. long)
- Sending time and day
Split your list into two equal segments, send each variation to half, and let the data tell you which version won. Over time, these incremental improvements compound into dramatically better performance.
Most email service providers have A/B testing built in. If yours doesn’t, find one that does — it’s essential.
Avoiding the Spam Folder
Spam filters are more sophisticated than most marketers realize. Landing in spam kills your email program regardless of how good your copy is.
Technical factors that affect deliverability:
- Email authentication (SPF, DKIM, DMARC) — set these up on your domain
- Sending from a domain with a good reputation
- Keeping your bounce rate low (clean your list regularly)
- Maintaining healthy engagement rates (low open rates signal to providers that your emails might be spam)
Copy factors that trigger spam filters:
- Excessive use of promotional words (“FREE!!”, “Act Now!!”, “100% Guaranteed”)
- All-caps in subject lines
- Too many images relative to text (spam filters read text, not images)
- Link-heavy emails with no substantial text
The best way to stay out of spam is to send emails that people genuinely want to receive. High engagement protects deliverability.
Examples From Campaigns That Work
The story email. Starts with a personal anecdote, transitions to the lesson, then connects to the offer. Effective because it doesn’t feel like a marketing email.
The curated roundup. “Here are 5 things worth reading this week.” Provides value with no sales pressure, builds trust, keeps subscribers engaged. Works especially well for newsletters.
The re-engagement email. Sent to cold subscribers: “I’ve noticed you haven’t opened our emails in a while. Either something isn’t relevant to you, or life just got busy. If you want to stay on the list, click here. If you’d rather unsubscribe, that’s okay too — no hard feelings.” This honesty reliably reactivates a segment and cleans the list of genuinely disengaged subscribers.
The launch sequence. 5-7 emails over 5-7 days, starting with the problem (PAS), building to the solution reveal, stacking social proof, addressing objections, then urgency close. Each email does one job in the sequence.
Pair these techniques with the structural formulas in our copywriting formulas guide and the content strategy in our newsletter writing tips for content marketers for a complete picture of email writing across formats.