What makes a cold email get replies
Open any rule to see why it matters.
Where these rules come from
This cold email checker is built on two sources: Y Combinator's cold email advice for founders, and patterns from emails that got positive replies across 40+ Scoutreach client campaigns. They agree on almost everything. Short beats long, specific beats clever, and one easy question beats a meeting request. Here is what the checker looks for, and why.
Keep it short: three sentences, under 60 seconds
A cold email should take less than a minute to read, and the best ones take about 15 seconds. A useful shape is three sentences: what you do for them, why it matters, and what you want. Most first emails behind positive replies in the Scoutreach data were one to three lines long. The checker flags anything over 120 words or more than six sentences.
Skip the backstory. Nobody needs your resume, your awards or your founding year in a first email. Skip the compliments too, like "big fan of your work". Give every email one goal and cut any word that does not serve it. If a sentence could go in an email to any company, delete it.
Subject lines: casual, short, relevant
Write the subject line the way a friend would. In Scoutreach's reply data, the most replied-to first-touch subjects were one to four lowercase words: "idea", "quick question", "interested?", "{{firstName}}, quick one", or their company name plus a topic. Headlines like "Unlock 3X Pipeline Growth This Quarter!" read like marketing and get treated like marketing.
Skip exclamation marks, all caps, emoji and words like "free" or "limited". Never fake a "Re:" on a first email. Save "Re:" for real follow-ups in the same thread. Test yours with the cold email subject line tester, or borrow one of these cold email subject lines that got replies.
The first line: what you do, or why it's them
The inbox preview shows your first line before they open. Don't spend it on "I hope this email finds you well" or "My name is Sam and I'm the founder of...". Two kinds of opener do well. One says what you do in plain words, framed as their result: "Would you be interested in closing 5 to 6 more general contractors on a performance basis?" The other gives a real reason it's them: "I was looking for captive insurance providers and came across {{company}}." A trigger works too, like a role they are hiring for, a launch or a new market.
Make it about them: their problem, in their words. Use plain words with zero jargon. If a buyer wouldn't say "leverage", "seamless" or "end-to-end solutions" out loud, don't write it. Read the email out loud before you send it.
Lead with your best proof
One concrete result beats a paragraph of claims: "We helped a company at your stage go from zero pipeline to 12 signed clients in 90 days." Use numbers, customer names or borrowed credibility like investors and past employers. A specific offer such as "10 to 12 qualified meetings a month" also works, because it shows exactly what they get.
One clear ask, on its own line
Make the ask explicit and put it on its own line, right before you sign off. Give the email one goal. "Are you free Tuesday? Or Thursday? Here's my calendar" asks for three things and usually gets none.
Don't ask for a meeting in the first email. Ask about interest and let them escalate: "Interested?", "Worth exploring?", "Open to it?" or "Want me to send it over?" In the Scoutreach data, positive replies came from these one-line interest checks. Specific time slots came later, once the prospect said yes.
Deliverability basics
Great copy does nothing in the spam folder. These rules matter as much as the words:
- No links or attachments in the first email. Tracking links, calendar links and PDFs are among the most common reasons cold email gets filtered. Offer to send them instead.
- Avoid spam-trigger words. "Guarantee", "free", "act now" and "100%" pattern-match to promotions. Run your copy through the spam word checker.
- Send as a real person. Use your name on a company domain, ideally a secondary domain with SPF, DKIM and DMARC set up and warmed before you start.
- Keep volume low per inbox, around 30 to 50 emails a day, spread across several inboxes.
- Clean your list. Bounce rates above 2 to 3% damage your sender reputation fast.
Follow up, and target better
Most replies come after the first email. Follow up 2 to 4 times, a few days apart, in the same thread. A plain bump like "bumping this up in case my last email got buried" is the most common email right before a positive reply in Scoutreach's data. If they still don't answer, don't take it personally. Check back in a few months. Ready-made versions are in the follow-up email templates.
Target better, not wider: 100 emails to good-fit prospects beat 1,000 to a random list. Start from one of the cold email templates, then run your version through the checker.
Frequently asked questions
What is a good length for a cold email?
Under 120 words, and ideally about three sentences: what you do for them, why it matters, and what you want. It should take less than 60 seconds to read. Most first emails that got positive replies across Scoutreach campaigns were just one to three lines.
How do I write a cold email subject line that gets opened?
Keep it casual, short and relevant, like a friend wrote it. One to four lowercase words work best: "idea", "quick question", "{{firstName}}, quick one" or their company name plus a topic. Skip exclamation marks, all caps, emoji, salesy words and fake "Re:" prefixes. You can test any subject line with the free subject line tester.
What words trigger spam filters in cold emails?
Words that sound like a promotion: "free", "guarantee", "100%", "act now", "limited time", "risk-free", "cash", "urgent" and "click here", plus all caps and repeated exclamation marks. One word rarely sinks an email on its own, but several together, combined with links and a new domain, add up. The spam word checker highlights each one with a safer alternative.
Should I include links in a cold email?
Not in the first email. Links, especially tracking and calendar links, are one of the most common reasons cold email lands in spam, and they ask the reader to do more work. Offer to send the link or case study if they reply, and save links for later follow-ups to people who engaged.
What's a good reply rate for cold email?
Most cold campaigns land between 1% and 5%. Under 1% usually points to a problem with the list, deliverability or the offer. Well-targeted campaigns with tight copy can reach 5% to 10%. Track positive replies and booked meetings, not just total replies, because those are what turn into pipeline.
Is this cold email checker free?
Yes. It is completely free, with no signup and no email required. The checker runs entirely in your browser, so your email is never sent to a server or stored. It is built by Scoutreach, a done-for-you cold email agency.