Professional Email Capitalization: Rules Every Writer Should Know
Email is the medium where small details carry outsized weight. A misplaced capital letter — or a missing one — is the difference between an email that looks competent and one that looks careless. Capitalization rules in email are not the same as in a printed letter or a blog post, and they vary slightly between formal business correspondence and casual internal messages. This guide covers the rules that apply to every part of an email: the subject line, greeting, body, sign-off, and signature.
Subject Lines: Sentence Case Is Now Standard
For decades, business writing guides recommended title case for email subjects because they were treated like document headings. That has changed. Today, almost every modern style guide — including the AP Stylebook, Mailchimp's content style guide, and Microsoft's writing style — recommends sentence case for email subjects. Sentence case reads faster on mobile screens, looks less like marketing spam, and matches the conversational tone that email now favors.
Subject line styles:
✅ Sentence case (recommended): "Quick question about the Q3 forecast"
✅ Title case (still acceptable, more formal): "Quick Question About the Q3 Forecast"
❌ ALL CAPS: "QUICK QUESTION ABOUT THE Q3 FORECAST" — triggers spam filters
❌ all lowercase: "quick question about the q3 forecast" — looks careless
Whatever style you pick, apply it consistently. A team that uses sentence case in 80% of its emails and title case in 20% looks disorganized. Pick a house style and stick with it.
Greetings and Salutations
The greeting line follows standard sentence rules: capitalize the first word, capitalize names and titles, and end with a comma (or, in the most formal correspondence, a colon).
- Capitalize the first word: "Dear," "Hi," "Hello," "Good morning."
- Capitalize the recipient's name and title: "Dr. Patel," "Ms. Johnson," "Professor Lin."
- Do NOT capitalize titles used generically: "Dear hiring manager" (not "Dear Hiring Manager") unless you treat it as a proper name.
- "Good morning" — only "Good" is capitalized in the greeting line.
Correct greetings:
"Hi Sarah,"
"Hello Mr. Tanaka,"
"Dear Dr. Williams:"
"Good afternoon, team,"
"To whom it may concern:" — only "To" is capitalized
Sign-Offs and Closings
The closing line follows the same rule as the greeting: capitalize only the first word, even if the phrase is two or three words long. This is a surprisingly common mistake — many writers capitalize every word out of habit.
| Correct | Incorrect |
|---|---|
| Best regards, | Best Regards, |
| Kind regards, | Kind Regards, |
| Thank you, | Thank You, |
| Looking forward, | Looking Forward, |
| Sincerely yours, | Sincerely Yours, |
Your name on the line below is, of course, fully capitalized as a proper noun.
Job Titles in the Body and Signature
Job titles are one of the most confusing areas of email capitalization. The rule: capitalize a job title when it directly precedes a person's name as part of their formal title, and lowercase it when it follows the name or is used descriptively.
Job title rules:
✅ "I spoke with Vice President Alicia Chen yesterday." (precedes name)
✅ "Alicia Chen, vice president of marketing, will lead the project." (follows name, descriptive)
✅ Signature block: "Alicia Chen / Vice President, Marketing" (formal title in signature — capitalized by convention)
❌ "I'm meeting our Vice President later." (used generically — lowercase)
Common Email Capitalization Mistakes
Mistake 1: Capitalizing Departments Generically
"Please send your request to marketing" — lowercase, because you're using "marketing" generically, not as the formal department name. "Please send your request to the Marketing department" can go either way; "Please contact our Marketing Department" treats it as a proper noun and is acceptable. Pick a house rule and apply it everywhere.
Mistake 2: Capitalizing Common Nouns for Emphasis
Writers sometimes capitalize words mid-sentence to emphasize them: "This is an Important Decision." This reads as old-fashioned and unprofessional. Use bold or italics for emphasis instead.
Mistake 3: ALL CAPS for Urgency
Putting "URGENT" or "ASAP" in all caps in the subject line is the email equivalent of shouting. It also triggers spam filters at many providers. Use "Urgent:" with a colon and normal capitalization instead.
Mistake 4: Lowercasing the Pronoun "I"
This sounds obvious, but mobile autocorrect frequently fails to capitalize "I" when typing fast. Always proofread before sending. You can paste your draft into our sentence case tool to normalize the whole email at once.
Email Signatures: Treat Them Like a Business Card
Your signature block is a mini business card. Capitalize your full name, your formal job title, your company name as the brand specifies (LinkedIn, IKEA, eBay, etc. all have unusual casing), and any credentials (MBA, PhD, CPA). Phone numbers, addresses, and URLs follow their own conventions — URLs should be lowercase.
Frequently Asked Questions
Is "Best Regards" capitalized?
No. Only the first word of an email sign-off is capitalized. Write "Best regards," not "Best Regards,"
Should I capitalize "Dear" in an email?
Yes — "Dear" is the first word of the greeting line, so it is always capitalized.
Is title case OK for email subjects in 2025?
Yes, it is still acceptable, especially for formal external correspondence. Sentence case is the modern default but title case is not wrong. Consistency within your team or company matters more than the choice itself.