How To
7 min read

How to Write a Professional Email Subject Line [With Examples]

Rachel Chaiet
January 10, 2023

You can't stress the importance of a great subject line enough. Subject lines are the first thing your recipient will read and set the tone for the communication. The subject line often determines whether recipients will even open it. In fact, more than 30% of recipients open emails based on the subject line. 

In a professional setting, subject lines may even be more important. You’ve got to incorporate a professional tone that will entice the recipient while not coming across as too aggressive or spammy. It’s a balance that can take some practice to achieve. However, with this article, you’ll learn everything you need to know about professional subject line success. 

Filled with practical examples for all types of professional emails, you’ll be ready to write your own subject lines in no time. So let’s boost those open rates and avoid the trash bin.

Best practices for professional email subject lines

When writing a professional email, there are certain best practices you’ll want to apply to your subject line. Following these tips will help ensure that your email makes a good impression, gets opened, and receives your desired response.

Make it short and sweet

Professional emails are targeting, well, professionals. Your recipient could be someone who doesn’t have all the time in the world and gets hundreds of emails per day. 

Short subject lines and to the point will help grab the recipient’s attention. Research shows that subject lines 41 characters or 7 words long are the ideal length. 

Optimize email subject line length

Let’s say you are sending an email to follow up after a job interview. Here’s an example of a subject line you could use:

“I enjoyed meeting with you, [interviewer’s name]!”

This subject line is short, on topic, and personal. It tells the recipient it’s meant for them and hints what is inside (a thank you note!).

Get specific and personal

Let your recipient know your email was intended for them by personalizing the subject line. It can increase open rates by 10-14%, so it’s worth including! 

You can personalize a subject line in several ways. However, the most natural option is often to include the recipient’s first name. You could also personalize subject lines with their city, job position, and interests. 

In addition, you’ll want to be specific, so your recipient can immediately know what your email is about. If you’re too general in the subject line, they might not realize that your email is something they are interested in. 

For instance, if you offer digital marketing services to B2B businesses and are writing an email to a lead, you could use a specific and personalized subject line example like this: 

“[First name], digital marketing could catapult growth for your B2B business”

The (social) proof is in the pudding

Before buying something new, many customers look at reviews, testimonials, and ratings. Social proof is how customers feel confident in your product's quality, making your business more trustworthy. So using social proof in your professional subject lines is a no-brainer! It can even help boost open rates and reduce unsubscribes. 

You can include social proof in your subject lines by citing a testimonial, mentioning an award you’ve won, partnerships with thought leaders or influencers, impressive stats, and media appearances. 

Here are two examples of how you can use social proof in an email subject line:

“This is the #1 digital marketing tool in 2022.”

“Check out our interview with The Guardian!”

Open-ended questions are professional subject line magic

When a question is posed, it’s second nature to answer it or want to know the answer. 

But if it’s a closed-ended question, there isn’t much opportunity to connect with your recipient. 

Open-ended questions in professional subject lines are a way to prompt curiosity in your recipient. If they can answer your question with a quick yes or no, why would they need to open the email? 

Go with open-ended questions where possible. 

Here is an example of an open-ended question for a professional subject line:

“What do you want to learn about retail trends?”

Be catchy without ending up in the spam folder

Your professional subject line should be catchy and intriguing enough to make your recipients want to open and see what’s inside. However, it would be best to avoid spam words that will lead your crafted email to the junk folder reducing your email open rate or coming across as spammy to the recipient. 

When writing your professional subject lines, you want to avoid words that over-sensationalize, over-promise, or use strange formats. 



Hubspot has a great list of spam words to be careful of. A few examples are ‘no purchase necessary’, ‘apply now’, and ‘don’t delete’. 

Some of the words included on the list might surprise you - seemingly innocent phrases such as ‘free’ and ‘now’. You can still use these words in your professional email subject lines; however, make sure to use them sparingly and with context.

Here is an example of a catchy subject line that avoids being too spammy:

“Some free tips to improve your SEO, [first name]”

Mind your manners 

A polite tone will get you far when it comes to professional email subject lines. Whether you’re making a networking email introduction or following up on a business prospect, you need to be courteous and respectful. 

You can’t be overly assertive or bold in professional email subject lines. Even if you’re following up after multiple unanswered replies, maintaining a friendly and polite tone will always be in your favor. 

Let’s say you are following up on an overdue invoice payment. While on the inside, you might be thinking, ‘Where is my money?!’, here is an example of a polite and professional email subject line:

“Your Design Services Invoice (#103) Is One Week Overdue”

Let’s look at another example. Say you’re writing to a potential investor and want them to consider participating in your next investment round. Here is an example of a professional and polite subject line:

“Please take an insider’s look into our next investment round, [first name]”

Copy AI’s tone changer tool is a fantastic way to ensure that your email subject lines are professional every time. It’s super easy to use and will give you several ways to incorporate professionalism and present your content in new and exciting ways. Check it out here.

Professional email subject line examples 

Professional email subject lines can fall into many different categories. Check out some great examples of the best email subject lines for professional emails for common situations in which you’ll want to write a catchy yet professional subject line. You’ll be able to tweak each email template and make them your own for professional emails.

Professional apology email subject lines

  1. We made a mistake 
  2. Thank you for your understanding [first name]
  3. Our sincere apology [first name]
  4. An apology from [your name or business name]
  5. We want to apologize [first name]

Professional email subject lines for work

  1. Attention Required: Facebook Ads
  2. Team Meeting Tomorrow
  3. Digital Marketing Update
  4. [Business name] Communication Plan
  5. September 2022 KPIs

Professional email subject lines for follow up

  1. Thank you for your time [first name]
  2. Next steps
  3. Pleasure meeting with you, [first name]
  4. Great speaking today. I wanted to add…
  5. Hello again from [your name or your business name]

Professional email subject line examples for job application

  1. Job application - Marketing Lead - [your full name]
  2. Resume attached for Graphic Designer position 
  3. Creative Director with fashion background would like to join your company
  4. Digital Marketer seeking a new opportunity at [business name]
  5. Hiring me will change your company’s sales results

Professional email subject lines for introduction

  1. Hi [first name], I love your work on [topic]
  2. I would love to collaborate [first name]
  3. Hi [first name], I’d like to introduce myself
  4. I’m a big fan of your work [first name]
  5. I’d love to connect with you, [first name]!

Professional email subject lines when sending a resume with reference

  1. Referred by [referee name] for Data Analyst role
  2. [Referee name] recommended I apply for the Personal Assistant role
  3. Referral from [referee name]: [your full name], Resume for Financial Advisor position
  4. Hi [recipient name], [referee name] suggested I get in touch
  5. Application for HR Manager: Referred by [referee name]

Professional email subject line when asking for advice email 

  1. I would love to hear your thoughts on [topic]
  2. Can you share your insights about [topic]?
  3. I loved your work on [topic]. Can I ask you a quick question?
  4. Do you have time to chat about [topic]?
  5. Can I share my ideas about [topic] with you?

Professional email subject line for complaint

  1. Unfortunately, I’ve been let down by your business
  2. I have a complaint about your service
  3. Can you please help me solve this issue?
  4. I am disappointed with my recent purchase
  5. Feedback on your service/product

Question-based subject line examples

  1. When can we chat about [topic]?
  2. [First name], what are your top 3 marketing goals this year?
  3. Do your product pages pass this test?
  4. What are you looking for in a Content Manager?
  5. Have you tried these three social media trends?

Professional email subject line for meeting request

  1. Requesting to meet this week
  2. Do you have time to meet this week?
  3. Please let me know when you’re free
  4. Can we schedule a quick meeting?
  5. Meeting to discuss a new project

Avoid these mistakes when writing subject lines for professional emails

Misleading subject lines

There’s nothing more annoying than getting an email with a misleading subject line. It’s a spammy tactic used to get recipients to open emails. But whether or not it goes very far is up for debate. Because if someone excitedly opens an email thinking it’s about one thing, they probably won’t be very happy to discover that they were misled. It’s also not very professional to pull this sort of stunt. 

That’s why you should always ensure your subject lines are on-topic. Try incorporating storytelling techniques into your email marketing practices. Think of the subject line as the title to the story you will tell inside of the email. 

Overusing emojis

There’s a time and a place for emojis. While they can enhance certain professional email subject lines, they’re not always necessary and should be used sparingly. 

A simple smiley face or thumbs up can be a great accessory to your professional subject line. However, it’s pretty hard to maintain professionalism if you add a bunch of heart-eyes emojis.

Keep it simple and professional by limiting emojis to the simple ones, or leave them out entirely. 

One-word subject lines 

Subject lines are a valuable communication tool. Using one word is never enough, and it comes off spammy. 

Professional emails should always have at least a few words, or a sentence, to complete a whole thought. Include enough information to give your recipient a clue about what is inside the email. 

Not thinking of mobile users

A whopping 42% of emails are opened on mobile. So when writing your professional email subject lines, you’ve got to consider this. 

Emails opened by device

Optimize for mobile by evaluating the character length of your subject line. Include the most critical information at the beginning of the subject line to limit the risk of it getting cut off and making zero sense to mobile users.

Forgetting preheader text

Preheader text is the short snippet that appears underneath the subject line when an email appears in an inbox. It’s a great way to give your recipient a bit more information about what’s inside the email. 

Remember to maintain the same professional tone and content when writing your preheader text.

Using too much punctuation!!!

Over-punctuating can come off as a bit aggressive or juvenile. You want your subject line to be simple and neutral in professional emails. Adding too many exclamation points or question marks can negate a professional tone. Keep it simple with one punctuation mark per sentence. 

Spelling or grammar errors

Even in short texts like subject lines, spelling and grammar errors have no place. Especially when you are trying to be professional, double-check your work to make sure that there are no mistakes to be found. 

Final thoughts on writing professional email subject lines 

An increase in opens, clicks, and conversions starts with a powerful, professional email subject line. Implement these strategies in your professional email marketing to craft subject lines that get results.

Want extra help with professional email subject lines? can help you write subject lines with a professional tone, faster and better. Try it out here.  

100x your output and create high-performing content with AI
Get started - It’s Free

Ready to level-up?

Write 10x faster, engage your audience, & never struggle with the blank page again.

Get Started for Free
No credit card required
7-day trial of Pro
90+ content types to explore