How to write a professional email

The 5-part structure

Every professional email that works follows roughly the same shape. Skipping a part is usually what makes an email feel incomplete or gets it re-read three times before the recipient understands what you want.

1. Subject line — specific enough that the recipient knows what's inside before opening it. "Question" tells them nothing; "Approval needed: Q3 budget by Friday" tells them everything.
2. Greeting — matched to the relationship. First name for colleagues and known contacts, "Dear [Title] [Last name]" for first contact with someone senior or external.
3. Context, in one sentence — what this is about, before you ask for anything. Readers process requests faster when they know the frame first.
4. The ask, stated plainly — one clear sentence. Buried asks ("I was thinking maybe at some point we could look at...") get skimmed past.
5. Sign-off — matched to tone: "Best," or "Thanks," for most business email; "Sincerely," for formal or first-contact correspondence.

Calibrating tone

Tone should shift based on who's reading, not personal habit. A useful test: would you say this sentence out loud to this person? If a sentence sounds stiffer on the page than you'd say it in person, it's usually over-formal. If it sounds too casual to say to your CEO, it's under-formal for that audience.

• Colleagues, peers: direct, warm, contractions fine.
• Clients, external partners: professional but not stiff — treat them like a respected colleague, not a stranger in a courtroom.
• Leadership, first contact, formal industries: measured phrasing, no slang, no exclamation points.

Mistakes that undermine otherwise good emails

• The wall of text. Three or more sentences without a line break loses the reader's place. Short paragraphs, one idea each.
• The buried ask. If the actual request is in the last sentence of the fourth paragraph, most readers already stopped reading.
• Vague subject lines. "Quick question," "Following up," and "Hi" all fail to signal urgency or content — see our guide to subject lines for specific alternatives.
• No clear next step. Every email expecting a reply should end with a specific question or action, not trail off.
• Over-apologizing. "Sorry to bother you, I know you're busy, this is probably a silly question but..." — cut all of it. State the question.

A five-second checklist before you hit send

• Does the subject line say what's inside?
• Is the ask stated in one clear sentence?
• Would you say this tone out loud to this person?
• Is there a specific next step or deadline?
• Could any paragraph be cut in half?

When the structure is right but the writing still takes too long

Knowing the structure doesn't make writing faster — most professionals still spend 3-4 minutes staring at a blank compose box per email. AI.Reply reads the thread you're replying to and drafts a complete, correctly-toned response in one click inside Gmail — Formal mode for the leadership emails, a lighter register for colleagues — so the structure above happens automatically instead of being something you have to remember every time.