Email subject lines are make-or-break.
It doesn’t matter how good your content is—if your subject doesn’t grab attention, the email is dead on arrival.
So how do the pros write lines that drive clicks? They use formulas.
Here are 10 battle-tested email subject line formulas that you can steal for your next campaign:
1. **The Curiosity Hook**
“You won’t believe what we found…”
Use this when you want to tease something interesting without giving it away.
💡 Example: “Why 83% of marketers are doing this wrong…”
2. **The Numbered List**
“7 ways to double your click-through rate”
Numbers work. People love lists. It feels organized, snackable, and achievable.
3. **The Quick Win**
“How to write a cold email in 2 minutes”
Show an immediate result or benefit.
4. **The Question**
“Is your welcome email killing conversions?”
Ask a provocative or relevant question. It prompts mental engagement.
5. **The Personal Callout**
“[FirstName], are you still interested?”
Use dynamic tags to add personalization. Feels like a real 1:1 message.
6. **The Urgency Play**
“⚠️ Only 12 hours left to claim this”
Inject urgency or FOMO to drive faster action.
7. **The How-To**
“How to boost email engagement in 2025”
Evergreen, straightforward, always works. Promise a clear outcome.
8. **The Mistake Callout**
“Avoid these 3 email marketing blunders”
No one wants to be wrong—pointing out mistakes piques interest.
9. **The Insider Tip**
“What top 1% marketers know about emails”
Position your content as exclusive or high-level.
10. **The Emoji Enhancement**
“🚀 5 quick ways to grow your list (starting today)”
Use emojis sparingly to add visual flair—don’t overdo it.
Final Tip
Test everything. A subject line that works for one audience may flop for another. Use A/B testing, and track open rates religiously.
Better subject lines = better first impressions = better results.
🧠 Pro Tip from MailGlider: Use our Subject Line Tester to get instant feedback on power words, length, and emotion score.
