Email subject lines: examples for questions, requests and more
A good subject line tells the reader what the email is about and what you need, before they open it. Here is a simple formula, the capitalization question settled, and examples for the emails people send most.
Put the topic and the action in a few words: "Question about invoice #1042," "Request: approve Friday's schedule," "Meeting Tuesday 2 pm: budget review." Front-load the important words, because phones cut long subject lines short. Use sentence case (capitalize only the first word and names) for everyday email; title case is fine but less common. Never write "Re:" or "Fwd:" unless it really is a reply or forward, and avoid all caps.
See also: Planning a launch? See the product launch email sequence. Writing a newsletter? See how to write a newsletter.
See also: More help: preheader text examples, should subject lines be capitalized? and emojis in subject lines.
A simple formula that works
[What it is about] + [what you need or when]
- Question about the March invoice
- Request: sign the lease renewal by Friday
- Update: new delivery date for order 5521
Three habits make almost any subject line better:
- Be specific. "Question" tells the reader nothing. "Question about Saturday's shift swap" tells them everything.
- Lead with the key words. Put the topic or deadline first, so it survives being cut off.
- Match the email. One topic per email and subject. If the topic changes, start a new email.
Purdue University's writing lab gives the same advice: include a meaningful subject line so the reader knows the topic and can decide when to read it.
Subject lines for a question
Say it's a question, and say what about. If you need the answer by a date, add it.
- Quick question about the Henderson proposal
- Question: is the parking lot open Saturday?
- Do you have the 2025 tax forms?
- Question about my order #48213
- Can we move Thursday's call to 3 pm?
- Question about the assignment due Monday (BIO 101)
- Which file should I use for the brochure?
A question can be the whole subject line, ending with a question mark. That is often the fastest email to answer.
Subject lines for a request
- Request: approval for new laptop by Oct 15
- Can you review my draft by Wednesday?
- Time-off request: Nov 24–26
- Request for a copy of my lease
- Help needed: printer on 2nd floor
- Action needed: sign the safety form by Friday
- Refund request for order #3390
Subject lines for a follow-up
Usually, reply in the same thread so the history stays together. If you start a new email, say what you're following up on.
- Following up: quote for kitchen remodel
- Checking in on my application for Office Manager
- Still interested? Your free estimate
- Next steps from Tuesday's meeting
- Reminder: invoice #1042 due Oct 31
Our follow-up email guide has full templates.
Subject lines for meetings
- Meeting request: 20 minutes about Q4 budget
- Invitation: team lunch Friday at noon
- Confirmed: call Tuesday 10 am ET
- Rescheduled: design review moved to Thursday
- Canceled: staff meeting Oct 12
- Agenda for Monday's board meeting
Always include the time zone if people are in different states.
Subject lines for job applications
Recruiters search their inbox by job title, so put it first. Follow the job ad's instructions if it asks for a specific subject.
- Application: Office Manager (Job #2291) – Maria Lopez
- Marketing Coordinator application – Daniel Kim
- Referred by Sam Patel: Account Executive role
- Thank you – Office Manager interview on Oct 8
- Following up: Office Manager application
Subject lines for sales and introductions
Keep them plain and honest. A subject that oversells, or pretends to be a reply, gets deleted or reported as spam.
- Idea for cutting your shipping costs
- Sam Patel suggested I reach out
- Quick intro: Tampa office cleaning
- Your free quote is ready
- Question about your front desk hours
Google's sender guidelines say subject lines should accurately represent the message content, and that senders shouldn't start subject lines with "Re:" or "Fwd:" unless the message really is a reply or forward. The FTC's CAN-SPAM guide also says commercial email must not use deceptive subject lines.
Capitalization: title case or sentence case?
Both are correct. Pick one and be consistent.
| Style | Example | Feels |
|---|---|---|
| Sentence case | Question about the March invoice | Natural, modern, conversational |
| Title case | Question About the March Invoice | Formal, like a headline |
| All caps | QUESTION ABOUT THE MARCH INVOICE | Shouting; avoid |
Most everyday work email uses sentence case. Microsoft's own writing style guide uses sentence-style capitalization for most titles and headings: capitalize the first word and proper nouns, lowercase the rest. Always capitalize names, product names, days and months.
One capitalized word for urgency is fine: "URGENT: server down." Use it rarely, or people stop believing it.
How long should a subject line be?
Short enough that the important part shows on a phone. Phones show fewer characters than desktop inboxes, and the exact cut-off depends on the app, screen size and font. That's why the key words go first.
- Too vague: Hi
- Too long: I wanted to ask you a quick question about the invoice that we sent last month
- Just right: Question about last month's invoice
Words that can trigger spam filters
No single word sends an email to spam, but hype does: "FREE!!!", "Act now," "Guaranteed," "$$$," all caps and lots of exclamation points look like junk to people and filters. Our guide to subject lines and spam words explains what filters really check.
Questions people ask
- What is a good subject line for a question email?
- Say it's a question and name the topic, such as "Question about invoice #1042" or "Can we move Thursday's call to 3 pm?"
- Should email subject lines be capitalized?
- Capitalize the first word and any names (sentence case). Title case is also correct but more formal. Avoid all caps.
- Should I put a period at the end of a subject line?
- No. Subject lines work like headlines and don't need a period. A question mark is fine for a question.
- Can I leave the subject line blank?
- Avoid it. A blank subject looks careless, is easy to miss, and is more likely to be treated as suspicious.
- Should I write "Urgent" in the subject?
- Only when it really is urgent and time-sensitive. Overusing it makes people ignore it.