How long should a cold email be?

Between 40 and 120 words. Reply rates fall steadily above 120 and sharply above 200. A cold email has one job, which is to earn a reply, not to explain the product.

The structure that fits

1. One line showing you looked at them (something specific, not “I came across your profile”).
2. One or two lines on the problem you solve for people like them, with a number if you have one.
3. One question, easy to answer with a yes or no.

What to cut

• Your company introduction. They can click your signature.
• Feature lists. Save them for the call.
• Links and attachments in the first touch. They hurt placement and nobody clicks them.
• “I hope this finds you well.” Everyone deletes it in their head.

Why filters care too

Long emails with multiple links and formatting look like newsletters. Short plain-text emails look like a person wrote them. Filters are trained on that distinction. The spam checker scores length for exactly this reason.