Guide from the Subject Line Tester
Sales Email Subject Line Examples
Every example on this page is invented to show a pattern. None of them is a real email, and none comes with a promised open rate. What matters is why each one works or falls short, so you can use the same thinking on your own subject line.
Six weak and better pairs
Each pair shows the same idea written two ways. The names and companies are made up.
A pitch versus the reader's priority
Weak: Double your pipeline with our new platform
Better: Onboarding backlog at Northline
The weak version is about your product and leans on a big promise. The better one names a problem the reader already owns, in the plain words a colleague would use.
Based on: Gong, 2025Gong / 30MPC, 2025
Shouting versus calm
Weak: QUICK QUESTION ABOUT YOUR TEAM
Better: Question about your support queue
All capital letters read like yelling. Normal case feels like a note from a person, and naming the topic tells the reader what the question is about.
Based on: Boomerang, 2017
A name alone versus a real topic
Weak: Sam, quick idea
Better: Renewal timing for the Denver team
A first name by itself does not show that the email matters to Sam. The topic does. You can keep the name, as long as the topic is there too.
A vague teaser versus a specific question
Weak: You won't believe this
Better: A gap in your returns page
A teaser promises something without saying what. Real curiosity points at one specific thing the reader can check or answer.
A fake reply versus an honest first note
Weak: Re: our conversation
Better: Your post about hiring in Austin
Adding “Re:” to a first email pretends you have talked before. Readers notice, and it costs trust. Name the real reason you are writing instead.
Writing practice, not a study result.
A long sentence versus a short note
Weak: I wanted to reach out to see if you might be interested in learning more
Better: Faster month-end close
The long version spends every word on you and gets cut off in most inboxes. The short one leads with the outcome the reader cares about.
Based on: Gong / 30MPC, 2025
What the better examples have in common
The first three points come from the research cited in the pairs above. The last two are writing practice.
- They are a few words long.
- They use normal capital letters.
- They name the reader's topic or problem, not your product.
- They are honest about what is inside the email.
- They would still make sense if a colleague had written them.
Based on: Gong / 30MPC, 2025Gong, 2025
Use them as patterns, not templates
Copying a subject line word for word rarely helps, because a subject that could be sent to anyone reads like a template. RAIN Group's prospecting research points the same way: visible research about the reader's situation beats a mail merge, and a researched detail tied to a real problem counts as personalization while a name or a company token alone does not.
So take the shape, not the words. Start from something true about the reader, then say it in as few plain words as you can.
Based on: RAIN Group, 2017Woodpecker, 2026
Check your own subject line
Type your subject line into the Subject Line Tester to see which of these patterns it follows. You get a plain-English grade, the reason behind each point, and a link to the research. It is free, and nothing you type is stored.
Try the Subject Line TesterSources
- Gong. Does cold email even work any more? Here's what the data says (2025). Read the source
- Gong / 30MPC. 4 Data-Backed Subject Lines to Get Your Cold Emails Opened (2025). Read the source
- Boomerang. The One Thing You Should Never Do In An Email Subject (Based on Data) (2017). Read the source
- Marketing Letters. Personalized subject lines in email marketing (2023). Read the source
- Marketing Science. Personalization in Email Marketing: The Role of Noninformative Advertising Content (2018). Read the source
- Psychological Bulletin. The psychology of curiosity: A review and reinterpretation (1994). Read the source
- Saleshandy. 15 Data-backed Cold Email Templates With Frameworks (2026). Read the source
- RAIN Group. Top Performance in Sales Prospecting (2017). Read the source
- Woodpecker. Cold Email Statistics Based on Sending Over 20M Cold Emails (2026). Read the source
Advice marked as writing practice is common sense for clear email, not a study result. See where all of our guidance comes from. No statistic on this page is invented.