Effective Email Subject Lines: 9 Best Practices and Examples

The email subject line is the text you see right after the sender name when your email reaches your inbox. It summarizes the main purpose of the email and makes you decide whether you will open the email. The professional email subject line should include all key information like topics and deadlines to help the recipient quickly understand the importance of the content.

Let's start with a few numbers. According to Invesp, 47 % of recipients open an email based on the email subject line. 69 % of recipients report emails as spam solely based on the email subject. Personalized emails are 22 % more likely to be opened than general ones.

What comes out of it? The email subject line might determine the destiny of your email. Spam, ignored, or opened. You had better take time and pay attention when creating it.

What does it mean for your business? Building trust and credibility. Higher open rates and higher engagement.

The subject line is the first impression that the recipient will have of the email. Below you will find a few tips on how to make the most of it.

How long should a subject line be? Almost half of the people consume emails on their mobile devices. If you write a long subject line, the whole text won't display on their phones. Therefore, summarize the content of your email into approximately 6-10 words, or 30-50 characters.

The Pew Research Center revealed that over half of internet users believe spam is a major issue. Your business must establish trust through email subject lines. How to do that? Get to know your audience and tailor the message to them. Use their name, location, company, recent project, or any other information you have. No one wants to read mass messages. Personal touch catches attention and has the potential to build a relationship.

Use powerful words and trigger emotional and psychological responses. A sense of urgency makes people to take action. Similarly, you can try to wake up the recipient's curiosity to open the e-mail. Or, engage the recipient by asking a relevant question.

The subject line should be a summary of your email. Get to the main purpose of your email already there. You don't need to say everything but make the recipient understand what the email is about and what value it brings to them. Ensure the subject line accurately reflects the email's content to avoid misleading the reader.

Include trending topics in the subject - people won't open your email unless they see a topic that resonates with them. It’s admittedly tough to tell the whole story in one line, but you can still stimulate interest by using the subject line to refer to a great story. Point out that the reader must open and read the email to learn more.

According to the Content Marketing Institute, our brains automatically organize information into a logical order and are therefore attracted to numbers. Taking this fact into account research showed that email subject lines that included numbers increased open and reply rates. 

They are much easier to proceed by our brain and much more easily visible than text. If possible use numbers to attract the reader's attention.

Make sure the subject line is free of spelling and grammatical errors. Why is this critical? If the subject line is riddled with such errors, the reader may become skeptical about the credibility of the rest of the email. Many of today’s email platforms contain built-in spelling and grammar checkers. So, it’s worth taking the time to turn on spell check and grammar check.

Talking about grammar, there is a question about email subject line capitalization. Do you know if the subject line should be capitalized or not? You have two options.

• Capitalize the subject the same as it would be a book title - that means capitalization of all words except minor words such as articles and prepositions. 

Example: "Dean, Your Feedback Needed on Project Plan"

• Capitalize only the first letter and leave the rest uncapitalized except any proper noun. 

Example: "Discover the last minutes and fly to North Africa”

Emojis can make your subject stand out. But they can have a negative impact as well. Consider the relevancy of emojis in the subject line. Think carefully about who the target audience is, and what your message is. Don't include them every time - use them rarely to save their power.

Improve your subject line constantly. Edit the current one, create several versions, and test them. Try which version works better by conducting A/B testing. You'll see what resonates best with your audience.

How should you write an interview follow-up thank you email? Start with “Thank you”. Additionally, you can mention the job role you applied for, the day of the interview, or any other relevant detail. You can also raise a question that came to your mind.

Here are a few examples: 

• Thank you for your time

• Thank you for this morning's interview

• Thank you - Product Manager

• Thank you + quick question about a skills test

If you want to reach out to the hiring team shortly after the interview, it's best to use above mentioned subject lines, expressing your thanks.

If you reach out to the hiring team because you haven't gotten any feedback for a while, it's best to reply to the last email thread. 

• RE: Interview for senior solution architect position on Wednesday (24/7/2024) at 1:00 pm

If your previous communication was via phone, try the following subject line examples:

• Interview status for Senior Solution Architect position

• Following up regarding the interview results of the Senior Solution Architect

A resignation letter is a formal statement of your resignation. You probably already had a meeting with your manager and now, you need to write it down as a confirmation for both sides. Since it is a formal, legal document, it should be straightforward, direct, and clear.

When crafting the subject line, use the word Resignation and include your name. An example of the resignation letter subject line is very simple.

• Resignation letter - Your name

• Your name - Resignation letter

A resignation letter is a formal document, whereas a farewell email is a final goodbye to all your colleagues. Its formality depends on your relationship with your colleagues and on the size of the company. Still, it is the last trace you make in the company.

• Farewell & thank you!

• Time to say goodbye

• Farewell, my friends

• Last goodbye

An introduction email subject line depends on the occasion it is devoted to. Therefore, choose the formality of your tone of voice based on the situation. Here are some examples you might use for good introduction email subject lines.

• Welcome to the [name] community

• It's nice to meet you

• Your journey starts here

• Welcome on board

Follow-up emails are important, as they will help you get noticed. You will increase your chances the recipient will reply to you. However, follow-up emails shouldn't be long. Make it brief and natural. 

• I've been thinking about what you've said, [name]

• I forgot to mention…

• [Name], quick question from our meeting…

• Here is the info I promised…

• Next steps for you and my team…

Networking emails can connect you to other professionals in your field. It is a great way to start a conversation with someone you can cooperate with in the future. Therefore, pay attention to the subject line, determining whether they will open the email and respond to you. You may reach out to someone you have never met before, or you can reach out to someone you met at some event and want to talk again. 

• Hi [name], I'd like to introduce myself

• This is [name] from [event]

• We met at [mutual connection]

• I love your work on [topic]!

• Can we catch up before [event]?

Sending a formal email to someone you haven't met yet? Outreach email has its specifics, including a subject line. Check on a few examples:

• Are you struggling with [pain point]?

• Can I help with [goal]?

• Want to overcome [common challenge]?

When applying for a new position, you want everything to be perfect. A perfect subject needs to be clear and specific about who you are and what you are applying for. 

• [Your name], Senior Solution Architect application

• Senior Solution Architect - [Your name]

An email’s subject line determines whether the recipient will open your email. People are more likely to read ones that are short, interesting, and unique. If successful, the subject line will help your company to increase engagement, web traffic, and leads.