Subject Line in Business Letters (Professional Email) | 5 Best Practices With Examples

Key Takeaways
The blog post provides valuable insights into crafting the perfect subject line for your business letter – a crucial yet often overlooked component. By understanding its purpose, length, format, and dos & don’ts, you can significantly enhance your professional communication and attract better response rates. Discover these tips and more to ensure your business letters won’t go unnoticed.


A subject line is the most crucial piece of information in an email. It’s the first thing recipients see when they open an email, and it’s what determines whether they’ll read it or move on.

Subject Line in Business Letter with examples
Subject Line in Business Letter with examples

So, how do you write effective professional email subject lines that will get your messages opened and read? This is exactly what we’re going to discuss in this article.

The Importance of Subject Lines in Business Letters (Professional Email)

Email subject lines are THE most critical part of your email because they are the first thing your recipients will see when they receive it. A good subject line will make your recipients open your email, while a bad one will cause them to ignore it.

Why Is The Subject Line in Business Letter (Email) Important?
Why Is The Subject Line in Business Letter (Email) Important?

Think of your subject line as a headline for your write-up. Just like a headline, it should be short, attention-grabbing, and descriptive of the content of the email. A good email subject line will also give recipients an idea of what to expect from the rest of the email, encouraging them to keep reading.

Write emails with nice titles but avoid sending emails after work hours – because of 5 damage it is doing to you.

The Secretes of Creating Successful Email Subject Lines

Your email subject line is your first (and maybe only) chance to make a good impression on your reader. In a few words, you have to tell them what’s inside and do it quickly. 

Are you feeling tense? No wonder many people freeze up when it comes time to write a subject line. But it doesn’t have to be that way. If you take time to understand what makes a great subject line, you can fill your recipients’ inboxes with messages they can’t wait to open.

So, let’s look at what makes a great email subject line, with some examples to help you get started.

professional subjects for emails - The best practices
Professional Subjects for Emails – The Best Practices

1. Keep it short and to-the-point

When it comes to email subject lines, shorter is almost always better. Yesware found in a study conducted on 265,000 template emails with subject lines between one and five words have the highest open rates.

The best email subject lines are brief and descriptive and give recipients a clear idea of the message. The subject line is vital for encouraging recipients to open an email, so it is worth spending time crafting one that will entice them. 

There are a few things to keep in mind when writing email subject lines:

  • Keep it short: Keep the subject line under 50 characters so it’s easy to read.
  • Use keywords wisely: Use specific keywords that accurately describe the content of the email. It will help recipients know what the email is about and whether or not they should open it.
  • Avoid using “spam” words: Words like “free,” “win,” and “urgent” can trigger spam filters, so it’s best to avoid them in your subject line.
  • Use personalization: Address the recipient by name or include other information that makes the email feel more personal. It can encourage recipients to open the email.

Here are a few examples of email subject lines that are short, descriptive, and personalized:

– “Improve your rankings and traffic”

– “Create a project budget to stay on track”

2. Use keywords

Your email subject line is your first chance to make a good impression on your reader. In a few words, you need to tell them what’s inside and, more importantly, why they should care. But with so much competition in everyone’s inbox, how can you ensure your email stands out?

One way is to use keywords. Like SEO for blog posts and webpages, using the right keywords in your email subject line can help your message cut through the noise and earn those all-important open.

Before you start adding keywords willy-nilly, it’s essential to do your research and understand which words will resonate with your audience. Brainstorm a list of potential keywords, then use tools like Google AdWords Keyword Planner and Google Trends to see how popular they are and whether they’re rising or falling.

3. Use numbers

Some marketing studies have shown that using numbers in email subject lines can increase open rates by up to 75%. It is because numbers tend to stand out in the inbox and indicate to the reader that the email contains information worth reading.

If you want to show how much work a reader needs to do (like the steps in a process), a low number works better because it makes the process seem faster and easier.


“How To Create a Small Business Website in 5 Simple Steps”

But suppose you’re giving the reader something of value. In that case, a higher number will work better because it makes the reader think your email is more valuable.


“9 SEO Best Practices To Improve Your Rankings”

Starting with a number, you are already providing value and quickly letting the reader know what they can expect by opening the email.

4. Use questions

A great way to engage your reader is to begin your email subject line with a question. Using questions in the email subject line will Intrigue the reader to know the answer and encourage them to open the email to get the answer. 


“Have you tried this new product yet?” 


“Are you interested in learning more about our company?”

5. Use emojis

Emojis are becoming increasingly popular and are a great way to add fun to your subject lines. Experian has found in one of their research that using emojis in the subject line increases the open rate for 56% of brands. You can find a variety of emojis on emojipedia website. 

However, using emojis doesn’t work well in formal business emails; most people agree. For example, using an emoji in your subject line might not be the best idea if you represent a law firm. Generally, it’s best to use emojis relevant to your industry or campaign.

Here are a few examples of brands that have used emojis in their subject lines:

Catchy email subject line using emoji (AppSumo Example)
Catchy email subject line using emoji (AppSumo Example)
Catchy email subject line using emoji (UptimeRobot Example)
Catchy email subject line using emoji (UptimeRobot Example)

Are you a user of Microsoft Outlook? You might be interested in How to Effectively Manage Outlook Inbox | 4 Actionable Steps That’ll Boost Your Email Productivity

9 Types of Email Subject Lines With Examples

We have talked enough about the recipe to cook a catchy email subject line. Now it’s time to give examples of different email subject lines. I’ve compiled a list of 9 different types of email subject lines, with examples, to help you learn how to write them for your business. Which of the following is the best subject line? That depends on the context, email content, and target audience.

1. The simple email subject line

This is the most common type of email subject line. It is direct and to the point and usually tells the recipient what they can expect from the email. 

For example:

– “Your order has shipped!”

– “Your order is on its way”

– “We have some new products for you”

– “You’ve been invited to join our VIP group”

2. The question email subject line

Asking a question in your email subject line is a great way to get your recipients to open your email. It piques their curiosity and encourages them to find out more.

For example:

– “Do you like free stuff?”

– “Who doesn’t love a sale?”

– “Which one of these is your favorite?”

3. The how-to-email subject line

People love learning new things, especially if it can help them somehow. That’s why how-to email subject lines are so effective. They promise to teach recipients something new they can use daily.

For example:

– “How to make that perfect cup of coffee”

– “How to style your hair like a pro”

– “How to get your kids to eat their veggies”

4. The list email subject line

This type of email subject line is similar to the how-to email subject line in that it promises helpful information. But instead of teaching recipients how to do something, it provides them with a list of things they can do (or, in some cases, should avoid doing).

For example:

– “The top 10 ways to style your hair”

-“5 foods that are guaranteed to give you energy”

-“3 workout moves you’re probably doing wrong”

5. Email subject line with urgency

Sometimes, you need to get your recipients’ attention immediately; an urgent email subject line can help. Deepak Gupta, the CTO and co-founder of LoginRadius, shared subject lines that convey urgency can increase open rates by up to 22%. A sense of urgency encourages recipients to open the email immediately. 

For example:

-“Hurry! The sale ends tonight!”

-“Last chance! Get 50% off today!”

-“Only 2 hours left!”

Another use case of this type of email subject line is to clarify that the recipient must act now to avoid a negative consequence.

For example:

-“Your Credit Card Is About to Expire”

– “Action Required: Your Domain Is About to Expire”

-“Your Subscription Is About to Run Out”

6. The funny email subject line

Funny email subject lines are great for building rapport with your subscribers and keeping them engaged with your content. They also tend not to be taken as seriously as other types of subject lines, which can be beneficial if you want recipients to read (but not necessarily act on) your emails.

For example:

-“You won’t believe what happened at my dog’s vet appointment today!”

-“I’m starting a diet tomorrow…wish me luck!”

-“My kids are driving me crazy…and I love it!”

7. The teaser email subject line

A teaser email subject line is similar to a funny one in that it’s designed to pique recipients’ curiosity and encourage them to open the email. But instead of being funny, teaser subject lines are mysterious or vague, which can be just as effective at getting people to open your emails.

For example:

Keep your eyes peeled tomorrow!

8. Actionable email subject line

These email subject lines promise the recipient that they will see a desirable outcome if they take a specific action.

For example:

– “Get Promoted in 30 Days”

– “Lose 10 Pounds in 2 Weeks”

– “Make $10,000 a Month Working from Home”

9. Email subject line provoking curiosity

These email subject lines pique the recipient’s curiosity by hinting at something juicy or exciting that awaits them inside the email.

For example:

– “You Won’t Believe What Happened Next…”

– “I Didn’t Believe It When I Saw It…”

– “Here’s the Shocking Truth About…”

Additional Examples of Email Subject Lines for Various Scenarios

Subject line for complaint email to HR

A few examples of the subject lines for complaint emails to HR are as follows:

  1. Formal Complaint: Harassment Incident in the Workplace
  2. Employee Complaint: Discrimination and Unfair Treatment
  3. Reporting Incident of Bullying by a Co-worker
  4. Concerned Employee: Requesting Action on Manager’s Inappropriate Conduct
  5. Complaint of Unprofessional Behavior by a Colleague

New arrivals email subject line

A few examples of new arrivals’ email subject lines are as follows:

  1. Fresh Off the Truck: New Arrivals in Store Now!
  2. Introducing our Latest Collection: New Arrivals for Spring
  3. Be the First to Shop Our New Arrivals – Limited Stock Available
  4. Get Ready to Upgrade Your Wardrobe: New Arrivals Just In
  5. New Season, New Styles: Discover Our Latest Arrivals

Labor Day sale email subject lines

A few examples of labor day sale email subject lines are given below:

  1. Celebrate Labor Day with Our Exclusive Sale – Up to 50% Off
  2. Labor Day Weekend Sale: Best Deals of the Year
  3. Last Chance for Labor Day Savings: Shop Now
  4. Hurry! Labor Day Deals Starts Tomorrow
  5. Labor Day Blowout Sale: Save Big on All Items

Fundraising email subject lines

A few examples of fundraising email subject lines are given below:

  1. Join Our Mission: Support Our Fundraising Campaign
  2. Your Donation Can Change Lives: Contribute Now
  3. Together We Can Make an Impact: Donate to Our Fundraiser
  4. Urgent Request: Please Support Our Fundraising Efforts
  5. Invest in Our Cause: Donate to Help Those in Need

Farewell or Goodbye email subject line to coworkers

Some examples of goodbye or farewell email subject lines to coworkers are as follows:

  1. Goodbye and Thank You: My Last Day at [Company Name]
  2. Saying Goodbye: It’s Been an Honor Working with You All
  3. Farewell and Best Wishes: A Bittersweet Goodbye
  4. Au Revoir: A Final Goodbye to My Wonderful Colleagues
  5. Saying Goodbye with a Heavy Heart: My Last Day at [Company Name]
  6. Farewell to My Second Family: Thank You for the Memories

Condolence email subject line

A few condolence email subject lines are as follows:

  1. With Deepest Sympathy: Sending Condolences for Your Loss
  2. In Memory of [Name]: Offering My Heartfelt Condolences
  3. Words Can’t Express: Condolences for Your Recent Loss
  4. Remembering [Name]: My Sincere Condolences to You and Your Family
  5. Sharing in Your Sorrow: My Condolences for Your Bereavement
  6. May Memories Bring Comfort: Offering My Deepest Condolences
  7. Sending Love and Support: My Heartfelt Condolences to You
  8. Honoring the Life of [Name]: My Sincere Condolences to Your Family


Your email subject line is your first — and maybe your last — chance to make an impression. So don’t take it lightly! Moreover, if you don’t want your email caught by the spam filter, you must craft the subject lines carefully. 

Follow the tips and professional email subject line ideas shared in this article, and you’ll be well on your way to writing compelling, successful email subject lines that will get your messages to read.

FAQ on Subject Line in Business Letter

  1. How to subject a professional email?

    To subject a professional email, the sender should include a brief, specific subject line that indicates the purpose of the email. It should also be clear, concise, and contain the main keywords that will get the recipient to open it.

  2. How do you write an email subject?

    The subject of an email is the line of text that appears in the inbox of the email’s recipient. It is intended to give the recipient a brief overview of the email’s content. The subject line usually determines whether the email will be opened. When writing an email subject, it is vital to be clear and concise. It should also contain the main keywords, creates a sense of urgency for the reader, and at the same time, be honest.

  3. What is an example of good subject line in an email?

    A few quick examples of good email subject lines are as below:

    Example 1: XYZ Blog’s Weekly Digest ## (Straightforward and to the point email subject line).

    Example 2: 4 BRAND NEW features & updates from Company XYZ (Announcement or Sharing Updates).

    Example 3: You won’t believe what happened at my dog’s vet appointment today! (Email subject line provoking curiosity).

    Example 4: Premium Plan – 1000 Credits Limit – Last 7 Days to Grab it! (Creating a sense of urgency in the recipient through the letter’s subject line).

    Example 5: Last 24 hours to grab this special offer ⏰ (Catchy subject line with the use of emojis).
    AppSumo has shared 80 best email subject lines with examples.

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