How long should a cold email be? What 34M emails show

Keep the first cold email under 100 words, and usually between 25 and 80. That is enough for one line on why you are writing to this person, one line on the problem, one line on what you do and one question. Follow-ups should be shorter still. The honest part of the answer is that the largest public dataset shows word count moving reply rates less than almost anything else you control. Cut words to make the email clearer, not to hit a number.

What the data actually says

The number you will see quoted everywhere is "50 to 125 words." It comes from Boomerang's 2016 analysis of more than 40 million emails. Every length in that band got a response rate above 50%. Replies fell slowly from 125 words to 500, stayed flat until about 2,000, and dropped more steeply for emails under 50 words.

The catch is that this was ordinary email, not prospecting. Boomerang is a Gmail productivity tool, and its users mostly write to colleagues and clients who already know them. No cold campaign gets 50% replies. Use the study for what it does show: people answer clear, short messages. Do not use it as a benchmark for outreach.

Hunter ran the cold-only version. It took campaigns sent through Hunter Sequences between 2022 and 2024, dropped any campaign with fewer than 50 emails, and removed campaigns with reply rates above 30% (likely warm lists) or under 0.5% (likely broken setups). That left 34 million emails.

Emails of 20 to 39 words won at 4.5%. Emails under 100 words averaged 3.9% against 3.7% for longer ones. Now look at the spread: the whole table, every band from zero to 200+ words, sits between 3.4% and 4.5%. Emails over 200 words did exactly as well as emails under 20. Hunter's own conclusion is blunt: if you can say the same thing in fewer words, try it, and otherwise stop worrying about the count.

Why short still wins in practice

If the averages are this close, why keep cutting? Because an average hides what the extra words are.

Length is usually a symptom. A 200-word cold email is rarely a rich, well-argued message. It is a 40-word email with a company introduction, a menu of services and a case study nobody asked for bolted on. The extra words are the wrong words. The long emails that do work are long for a reason: Hunter found a 115-word campaign with a 15% reply rate, a piece of link outreach that genuinely needed the context.

The reader decides in the preview. On a phone, the inbox shows the sender, the subject and a line or two of text. If those lines are about you, your company and your years in business, most people never open the rest. The first sentence has to be about them.

A short email asks one thing. The same Boomerang study found that emails asking one to three questions were 50% more likely to get a response than emails asking none. A short email has room for exactly one question, and nothing to bury it under.

Hunter's dataset has a nine-word campaign that got 13% replies: "Hey {{first_name}}, are you still selling {{product}}? Cheers." It worked because the question was the whole point and the list was right for it.

What to cut: a before and after

Here is a typical first email, 139 words:

Hi Anna, My name is Mark and I'm the Head of Growth at Brightline, a leading provider of revenue operations consulting for B2B SaaS companies. Over the last eight years we have helped more than 120 companies across North America and Europe streamline their sales processes, improve forecasting accuracy and build scalable outbound engines. I came across your profile and noticed that Fieldnote recently raised a Series A, congratulations! Companies at this stage often struggle with building a repeatable pipeline, onboarding new reps and keeping the CRM clean as the team grows. We offer a range of services including CRM audits, outbound playbooks, rep onboarding programs and fractional RevOps leadership. Our clients range from seed-stage startups to public companies. Would you be open to a 30-minute call next week to explore whether there might be a fit? Best, Mark

And the same email at 54 words:

Hi Anna, Saw Fieldnote closed its Series A and is hiring three AEs. The quarter after a raise is usually when the CRM stops matching reality: new reps, no shared stages, forecasts by gut feel. We fix that for SaaS teams your size in about four weeks. How are you handling it today? Mark

What went: the self-introduction, the years and client count, the service menu, the "leading provider" line and the 30-minute call. What stayed: a reason that is specific to Anna, the problem described the way she would describe it, one sentence on what Brightline does, and a question she can answer in one line without committing to anything.

The call request is the cut that matters most. Asking a stranger for half an hour of their week is a big ask for a first message. Asking how they handle something today is not. More on that in how to end a cold email.

A structure that fits in 80 words

If a line does not fit one of these slots, it is a candidate for deletion. Read the draft and ask of each sentence: would the reader miss it if it were gone? Most of the time the answer for the second paragraph is no.

Follow-ups: shorter than the first email

Follow-ups sent in the same thread do not need to restate anything. The first email is right below them. Our position is 20 to 50 words, with one new thing in each: a relevant fact, a short example, a different question. "Just bumping this to the top of your inbox" adds nothing and reads like it. Three follow-ups is plenty; the reasoning is in how many follow-ups before giving up.

When a longer email is the right call

Short is the default, not a law. Write more when:

• They asked for detail. A prospect who replied "send me more info" wants specifics, not another teaser. See how to respond to "send me more info".
• The proof is the hook. For a technical buyer, one concrete result or a short description of how something works can be the whole reason to reply. Keep it to the one proof that matters.
• There is a warm path. A referral or a shared contact earns you a few more sentences of context.

Even then, the first line still has to be about them, and there should still be one question.

Length is the least of it

If your reply rate is well under the benchmarks in what is a good cold email reply rate, word count is unlikely to be the reason. Check who is on the list and whether the email gives each person a reason to answer, then look at when you send.

Where Nitrino fits

The hard part of a 50-word email is the first line, because it has to be true about one specific person, and writing that line for each of 300 people takes a day. Nitrino does that research before every first letter: it reads the person's LinkedIn profile, their company's site and a few web searches, then writes a separate letter for that person. When replies come in, it answers them in the account owner's voice and calls a human only when a decision is needed. If writing short, specific emails at volume is where your outreach stalls, see how Nitrino works.