Email Marketing
Writing Email Subject Lines That Get Opened (With Examples)
No matter how good your email is, an ignored subject line means it is never read. The subject line, preview text, and sender name are the three things a subscriber sees before deciding to open. Get them right and everything downstream improves.
The three things that drive opens
Subscribers decide to open based on the sender name (do I recognize and trust this?), the subject line (is this relevant or interesting?), and the preview text (what is the first line?). Optimize all three together—a great subject line wasted next to an unrecognized sender still gets ignored.
Principles of subject lines that work
- Be specific: “3 ways to cut your shipping costs” beats “Our newsletter.”
- Keep it short: aim for around 40 characters so it is not cut off on mobile.
- Create curiosity or value, not clickbait that the email fails to deliver.
- Personalize when you can—names and relevant products lift opens.
- Use urgency honestly; fake countdowns erode trust fast.
Proven formulas you can adapt
- The how-to: “How to [achieve outcome] without [pain].”
- The number list: “5 [things] that [benefit].”
- The question: “Still paying too much for [thing]?”
- The offer: “24 hours: 20% off everything.”
- The curiosity gap: “The mistake costing you customers.”
Don’t forget the preview text
Preview text is the snippet shown after the subject line. Treat it as a second subject line—extend the hook rather than letting the email client pull a random first line like “View in browser.” Together, subject and preview should make one compelling promise.
Avoid spam triggers
ALL CAPS, excessive punctuation (!!!), spammy words like “FREE $$$,” and misleading subjects can hurt deliverability and trust. Modern spam filters weigh many signals, but misleading subject lines also violate CAN-SPAM. Write honestly and your inbox placement benefits too.
Key takeaways
- ✓Sender name, subject line, and preview text together drive opens.
- ✓Be specific, short, and honest—avoid clickbait.
- ✓Use proven formulas: how-to, list, question, offer, curiosity.
- ✓Write preview text as a second subject line.
- ✓Avoid caps, excessive punctuation, and spam-trigger words.
Valter Brandt
Email & Lifecycle Marketing Lead
Valter Brandt leads email and lifecycle marketing at ThisCom, helping small and medium businesses build automated, high-deliverability email programs that drive revenue.
Frequently asked questions
How long should an email subject line be?+
Aim for roughly 40 characters or fewer so it is not truncated on mobile devices, where most email is opened. Front-load the most important words.
Should I use emojis in subject lines?+
A single, relevant emoji can help your email stand out, but overuse looks spammy and renders inconsistently across clients. Test with your audience and use them sparingly.
Why are my open rates unreliable now?+
Apple Mail Privacy Protection pre-loads images, which inflates open rates. Use opens as a directional signal and rely on clicks and conversions to judge real performance.
What words should I avoid in subject lines?+
Avoid ALL CAPS, excessive punctuation, and classic spam phrases like “FREE $$$” or “act now,” as well as anything misleading—both for deliverability and to comply with anti-spam laws.
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