The part that decides whether it is read.
WHAT A SUBJECT LINE MUST DO
Tell the reader what it concerns Indicate whether action is needed
WHAT MAKES ONE EFFECTIVE
Specificity The key noun early An indication of urgency where genuine
WHAT EXAMPLES LOOK LIKE
- Approval needed by Thursday: supplier contract
- Outage resolved: summary and next steps
- Invoice 4417: payment overdue
WHAT MAKES ONE INEFFECTIVE
Hello Quick question Following up Urgent, where it is not Nothing at all
WHY VAGUE ONES FAIL
They are deprioritised and unsearchable.
WHAT TO CONSIDER
That the subject is how the message is found in a year.
WHAT PREFIXES HELP
Action needed For information Decision required
WHY
They let readers triage without opening.
WHAT TO AVOID
Marking everything urgent
WHY
It stops meaning anything.
WHAT TO DO WHEN A THREAD CHANGES TOPIC
Change the subject, or start a new thread.
WHAT TO DO FOR RECURRING MESSAGES
Use a consistent format.
WHAT EXAMPLE SHOWS IT
Weekly update, with the date.
WHY
It makes them findable as a series.
WHAT TO CHECK
That the subject still matches the content before sending.
