A subject line is the tiny opening into a business email. Before the reader reads the salutation, the request, the reference to an attachment, or the sign-off, they see a few words saying whether this message is high-priority, standard-issue, informational, or action-oriented. If the subject line is vague, you are starting the email with added workload for the reader.
A lot of inexperienced business writers consider the subject line an afterthought. They create the entire email first, and then insert a broad subject line like “Question,” “Update,” or “Important.” These subject lines may feel safe, but they do not say the goal of the message. A reader who receives several emails a day has to open it before learning the topic, and that can make a straightforward request feel cluttered.
A better subject line often answers a single essential question: what must the recipient understand before opening the email? “Question,” for example, is vague, but “Question About Friday Meeting Notes” adds helpful context. “Documents” is not clear; “Invoice Documents Attached For Review” states the contents of the email and the probable action. The subject line need not tell the entire story, and only need to convey the message goal.
One tip is to create three subject lines for the same email before deciding on a final choice. You can start with an initial draft. The second iteration should include context such as a date, project, meeting, file, or request. The third draft should cut words while retaining the key information. The first draft may read “Follow-up,” the second “Follow-up About Contract Comments,” and the third “Follow-up On Contract Comments.” Rewriting in this way allows you to see the difference between a tag and a good subject line.
The length matters. A subject line may be too narrow, or too long to scan easily. The best subject line contains the most relevant information toward the front. If you are writing about a deadline, make sure the deadline information is easily readable. If you are sharing a file, be sure to refer to the file if the reader is to take a further step. “Updated Schedule Attached For Review” is better than “Please See The Attached File,” because the former indicates a specific document and action required.
The tone should also be represented in the subject line. This need not be dramatic, but it should not be aggressive. If there is not a need for immediate attention, do not insert the word “Urgent” or “ASAP” in the subject line. For most business communication, a neutral tone is more suitable; “Reminder: Team Feedback Due Thursday” works better than “Need This Now.” A courteous subject line can prepare the recipient for a courteous email.
Finally, you should check the subject line with the email text. Does the subject line reflect a question, response, update, clarification, or attachment? Does it feature one important piece of information without overloading? Is the topic of the message clear to the reader if they only saw the subject line in an inbox? If so, the email should feel much more streamlined.