Getting someone to open your cold email is half the battle. Your subject line is the first thing they see. If it doesn’t grab attention, your email will sit unread or go straight to the trash.
This guide will show you how to craft subject lines that increase open rates. It’s practical, simple, and filled with examples.
Why your subject line matters
Your subject line is like a movie trailer. If it’s boring, no one buys a ticket. It needs to spark curiosity, offer value, or feel personal.
People receive dozens of emails daily. Most get ignored. A great subject line makes yours stand out.
Think about your own inbox. What makes you click? Urgency? Personalisation? A little mystery? The same applies to your prospects.
Now, let’s break down how to write subject lines that work.
1. Keep it short and clear
Long subject lines get cut off, especially on mobile. Aim for 6-10 words. Get to the point fast.
Good examples:
● "Quick question about your sales process"
● "Ideas to boost your [specific goal]"
● "Saw this and thought of you"
What doesn’t work:
● "Exciting opportunity that you can’t afford to miss out on!" (Too long)
● "Hello, my name is John and I wanted to introduce myself…" (Too vague)
A subject line should give a reason to open, not explain the whole email.
2. Use curiosity (but don’t be clickbait-y)
People love a little mystery. The trick is to make them curious without being misleading.
Good examples:
● "You’re missing out on this easy fix"
● "I noticed something about [their company]"
● "Is this your next big opportunity?"
Avoid these:
● "You won’t believe what happened next!" (Too gimmicky)
● "URGENT: Open now or regret it forever!" (Too dramatic)
Make your reader curious but also give a hint of what’s inside.
3. Personalisation works wonders
Emails with a personal touch get more opens. Use the recipient’s name, company, or a relevant detail.
Good examples:
● "[First Name], a quick idea for [Company]"
● "Loved your post on [topic] – a thought for you"
● "[Company] + [Your Company] = Better Results"
People respond better when they feel the email is just for them.
What about AI-generated emails?
If you use tools like an AI email signature generator, your emails might already look professional. But that’s not enough. Even with automation, your subject line must feel human and personal.
AI can help with structure, but you need to add a touch of personality.
4. Use numbers or data
People love numbers because they promise clear value.
Good examples:
● "3 ways to double your sales this quarter"
● "How we increased leads by 47% in 30 days"
● "5 trends shaping [industry] in 2024"
Numbers stand out in crowded inboxes.
5. Make it relevant to their needs
A good subject line speaks to what your recipient cares about.
Good examples:
● "Struggling to find good leads? Try this"
● "A faster way to close deals"
● "How [competitor] is getting ahead – and how you can too"
Avoid making it about you. Instead of "We offer great marketing solutions," try "A simple way to get more leads."
6. Try a friendly, casual tone
You don’t always have to sound formal. A conversational subject line feels more natural.
Good examples:
● "Mind if I send this over?"
● "Thought you’d find this useful"
● "Quick question about [topic]"
People like reading emails that feel like they’re from a real person, not a robot.
Testing and tweaking your subject lines
Not every subject line will work the same way for every audience. Test different styles and see what gets the best response. A/B testing is simple. Send two versions of your email with different subject lines and see which gets more opens. If a subject line flops, tweak it. Small changes can make a big difference.
One last tip: If you’re attaching something important, make it clear. "Please see attached file" works well, especially when sending reports, proposals, or presentations. People appreciate clarity. If they know an attachment is included, they’re more likely to check.
Final thoughts
Your subject line is the key to getting your email read. Keep it short, clear, and relevant. Make it personal when possible. Use curiosity and numbers wisely. And always test what works best.
A great subject line can be the difference between a reply and being ignored. Use these tips to improve your cold email game today.
Copyright 2025. Article made possible by Easy Promo.