Subject line

The subject line is the sentence a subscriber sees before deciding whether your email deserves attention. It competes in a crowded inbox against every other sender, which is why it has outsized influence on open rate relative to the seconds it takes to write.

The reliable principles are unglamorous: clarity beats cleverness, front-load the meaning because mobile clients truncate, and avoid misleading promises or formatting that makes the message hard to read. A clear subject line helps readers decide whether the edition is relevant; test wording with your audience instead of assuming a universal winner.