Which of the following is NOT a characteristic of professional email etiquette?

• A. Clear subject line
• B. Respectful greeting
• C. Concise body
• D. Unclear or inappropriate tone

Answer: (D)

Professional email etiquette hinges on communicating with clarity, respect, and efficiency. A subject line that clearly communicates the topic helps the reader quickly understand the purpose. A respectful greeting sets the right tone from the start. A concise body delivers the message without unnecessary fluff, making it easier for the recipient to respond. The tone should be clear and appropriate; when tone is unclear or inappropriate, the message can be misread or come across as disrespectful, which undermines professional communication. Therefore, the statement describing tone as unclear or inappropriate is not in line with professional email etiquette, whereas the other practices align with good etiquette.