Email Subject Line Truth (One Hook Changes Everything!) Most emails fail before they’re ever read — not because the content is bad, but because the subject line doesn’t spark curiosity. If the subject line doesn’t pull attention, the email might as well not exist. Your subject line has one job: create just enough intrigue to earn the open. It doesn’t need to explain everything. It needs to make the reader want to know more. When curiosity is triggered, open rates rise naturally. Small tweaks her