How to Write Email Subject Lines that Persuade

Writing great email Subject lines is the single most important skill you can develop to improve your effectiveness with email communication. The Subject line is the first—and occasionally the only—element of an email that readers notice. By writing a persuasive subject line, you can help your readers identify the importance of your message and drive action.

Here are a few suggestions to write a great Subject line in every email:

• State the objective of your email in a meaningful Subject line. Give your readers a clue of what your email is about and the response you expect.
• The best Subject lines constitute the two key attributes of the email: [Context / Project] + [Action required / Message summary] E.g., “Need MATLAB help: how can I calculate 3D distance,” “Alternator repower: recommended solution,” and “Thank you for your insightful comments at the customer forum on Friday.”
• Avoid indistinct and elusive Subject lines like “Hi,” “One more thing…,” “FYI,” “Can you do this,” or, “Help, please???”
• Compose the Subject line after you compose the body of an email. The process of writing the body of the email will help clarify the key message you want to convey and the action you expect.
• Prefix the Subject with an ‘URGENT’ if the matter is urgent.
• Do not write the entire Subject line in ALL CAPS—this is the digital equivalent of shouting. Moreover, phrases in ALL CAPS are harder to read.
• For shorter quick messages, try composing brief, all-in-the-subject-line emails. E.g., “Friday’s lunch: rescheduled to 1:00 PM [eom]” or “Reminder: feedback reports due by noon. [eom].” Adopt a few standard conventions and abbreviations (e.g., EOM for end of message) in your team.
• When replying to emails, change the Subject line if the context of an email thread has changed during the course of the thread or if the Subject line in the original email was irrelevant or unclear.
• Avoid discussing multiple topics in a single email. Send multiple emails, each with its own, meaningful Subject line.

Keyword(s): email, email communication, effective communication