How long should a cold email be?

A cold email should typically run well under 100 words — commonly somewhere between 50 and 90. The first email in a sequence can use the upper end of that range; follow-ups should be shorter still, sometimes two or three sentences. The email's job is to earn a reply, not to close a deal, and every word past that job works against it.

Why do short emails win?

Because of how cold email is read. Your message arrives unrequested, usually on a phone, in a gap between things the recipient actually cares about. You get a few seconds of preview text and, if that survives, a few seconds more. A long email announces its cost before it makes its case: when a recipient sees a wall of text from a stranger, then the decision to skip is made before a single sentence is read. A short email can be judged in full within the attention it is actually given.

There is a second reason, less discussed. Length is where sellers hide. It feels safer to include the company background, the three service lines and the two proof points — but that safety is for the sender, not the reader. The discipline of 90 words forces you to decide what the one relevant claim is. If you cannot make the case briefly, the problem is usually the targeting or the offer, not the word count — a distinction The Complete UK B2B Outbound Playbook treats as the difference between copy problems and campaign problems.

What do those 90 words need to do?

Three jobs, in order. First, prove relevance: an opening line that shows the email was written for this firm, not sprayed at a list. Second, make one plain claim: what you do, for whom, and the outcome — stated in when-X-then-Y language rather than adjectives. Third, make one low-friction ask: a question that can be answered from a phone in one line, not a demand for a 30-minute meeting with a stranger.

Notice what is absent: no company history, no feature list, no attachments, no three links, no second ask. One observation, one claim, one question. Formatting does quiet work too — sentences under twenty words, paragraphs of one to three lines, white space that lets a phone screen breathe.

Does length change across the sequence?

Yes, and in one direction: down. In a four-email, fourteen-day sequence, the opener carries the full case in up to 90 or so words. The second email is a nudge in the same thread — two or three sentences, because its only job is to resurface the first. The third introduces a new angle and can stretch slightly to carry it. The fourth closes the thread in a few lines. Follow-ups do most of a campaign's work, but they do it through timing and persistence rather than volume of prose.

The mechanism, stated plainly: when an email's job is to introduce, then it gets the word budget; when its job is to remind, then it gets a fraction of it; when a prospect replies, then the sequence stops and the length rules expire — a reply to a warm conversation can and should be as long as the question deserves.

How does length show up in the numbers?

Indirectly but visibly. Length is one of the first suspects when positive replies sit below the 3% threshold that means fix the campaign — though it is rarely the primary culprit; list and offer usually are. What length reliably affects is the shape of replies: shorter emails tend to draw faster, shorter, more conversational answers, which are exactly what a pipeline wants at the top. If you track the weekly numbers described in Outbound KPIs: the five numbers that matter weekly, test length the honest way — one variable, one campaign, two weeks — rather than by instinct.

Should you re-litigate length every time you write?

No — decide it once and move on. Length is a perfect candidate for a standing rule of the kind covered in decision rules: pre-deciding your way out of overwhelm: openers under 90 words, nudges under 40, no exceptions without a written reason. The rule saves you from the slow creep whereby every stakeholder adds a sentence and the campaign gains thirty words a month. It also makes delegation possible: a rule a junior can apply beats taste only you possess. Whether you then run the writing yourself or hand it to someone else is the build-and-handover vs managed outbound question — but under either model, the emails stay short, because the reader's attention span does not care who operates your sending tool.

Short is not a style preference. It is what the medium's economics demand.

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