Subject Lines

A subject line has one job: get the email opened by someone who might genuinely care. Getting it opened by everyone is easy and worthless — a misleading subject produces an open, a moment of irritation, and sometimes a spam complaint.

Manage expectations before starting. Subject lines are the least consequential variable in cold outbound, well behind audience, offer and first line. They're the most tested because they're the easiest to test. If reply rates are the problem, the subject line is rarely the cause.

What works

Short. Three to five words. Mobile clients truncate around 35 to 40 characters, and most cold email is first seen on a phone.

Lowercase or sentence case. Title Case reads as a newsletter. quick question looks like a person typed it; Quick Question About Your Sales Process looks like a campaign.

Specific to them. The strongest subject lines reference the thing the email is actually about.