Should Email Subject Lines Be Capitalized: Understanding Email Best Practices

Should Email Subject Lines Be Capitalized

Within today’s corporate scenario, electronic mail is of paramount importance, functioning as the main conduit for crucial activities such as sharing propositions, sealing agreements, and broadcasting updates. As we traverse this technological age, the effectiveness of an email is mainly hinged on one vital component – the subject line. Please note, all links stay embedded and unaltered.

What if capitalizing your email subject lines could be the game-changer in standing out from a cluttered inbox? Let’s explore why capitalization matters for email subject lines and its advantages and disadvantages.

Stay tuned as we unravel how minor tweaks make major impacts!

Key Takeaways

  • Capitalizing email subject lines can help improve open rates and catch the attention of recipients.
  • Consistency in capitalization reflects professionalism and brand identity.
  • Different capitalization styles can convey tone and urgency, but it’s important to consider readability and current email trends.

Understanding Email Subject Lines

Understanding Email Subject Lines

Email subject lines play a crucial role in email marketing – they’re like an ad for your emails. These lines convey the email’s content, helping recipients decide if they want to read it now, later, or ignore it. However, crafting catchy and clear subject lines is no easy task.

Emails with short, engaging, and clear subjects often have higher open rates. So, it’s best to limit them to 50 characters. Additionally, using numbers in your subjects could improve open rates by 57%, and personalization could lead to a 50% increase in open rates. Therefore, investing time in crafting good subject lines can significantly boost your email marketing strategy!

Watch this video for more insights

The Importance of Email Subject Line Capitalization

Importance of email Subject Line Capitalization

Proper capitalization of email subject lines is essential for several reasons. Firstly, it reflects positively on your brand’s professionalism and attention to detail. Secondly, consistent capitalization helps establish a clear brand identity, allowing recipients to easily recognize your emails. Lastly, your subject line’s capitalization can indicate the tone or urgency of your email, helping recipients prioritize which emails to open first.

Watch this video to learn more

Consistency and Commitment

Consistency is key in crafting email subject lines. If you choose to capitalize every word or prefer sentence case capitalization, stick with it. Consistent styling aligns with your brand identity. For instance, if your brand has a playful tone, lowercase subject lines might work best. Alternatively, if your tone is formal, title case might fit better.

However, sudden changes can confuse your readers. Also, consider how spam filters interpret your capitalization styles when crafting your subject lines.

Brand Identity

Your branding sets you apart. How your email subject lines are written plays a crucial part in brand representation. Using capital letters can make your brand appear strong and bold. But be careful! Overusing them might seem like you’re shouting at people.

Your brand’s personality could also resonate with lowercase letters. Regardless, always stay true to your brand’s identity with each email you send.

Tone Indication

The style of your subject line sets the tone for your email. Overusing capital letters might seem like you’re shouting, scaring away readers, and triggering spam filters. Lowercase letters, on the other hand, creates a friendly and casual feel.

Tailoring your capitalization style to your message type and reader demographics can significantly improve open rates.

Types of Email Subject Line Capitalization

Email Subject Line Capitalization

There are several ways to capitalize email subject lines, each contributing to various effects and purposes. Let’s dive into these styles to understand their impact on your marketing strategy and open rates.

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Title Case

Using title case capitalization can make your subject lines more powerful and visually appealing. By capitalizing the main words in your subject line, you can draw attention and create a sense of importance. If you opt for using title case, ensure you apply it consistently across all your subject lines.

Sentence Case

In sentence case only the first letter is capitalized, contributing to a friendly and approachable tone. Research suggests that simple and straightforward subject lines result in higher open rates. So, if you want to create a sense of familiarity and better connect with your audience, sentence case might be your best bet.

NY Times Style

In the New York Times style of capitalization, all major words except for articles, conjunctions, and prepositions are capitalized. This professional and grammatically correct style can guarantee a polished and sophisticated look for your emails, catching the audience’s attention without sacrificing readability.

AMA Style

AMA Style follows proper noun capitalization rules, capitalizing only the first word’s first letter. This approach creates clear, concise subject lines that are easy to read.

Case Study: The Impact of Capitalization on Email Open Rates

Email Open Rates

A case study by John Oszajca discovered that lowercase subject lines got 35% more opens and clicks. Moreover, the analysis of emails from top email experts showed that while 60% of subject lines use sentence-case capitalization, only 6% use all lowercase. Making liberal use of action words like “get,” “watch,” and “join” can also make your subject lines more compelling.

However, you must avoid usage of all capitals as it is seen as shouting and can trigger spam filters.

The Debate: Should Email Subject Lines be Capitalized?

Whether or not you should capitalize your subject lines depends on your target audience, branding, and personal preference. You’ll find arguments on both sides:


  • Readability: Capitalizing the first letter of each word in the subject line improves readability.
  • Sender preferences: Some people believe that capitalized subject lines add professionalism and enhance brand identity.


  • Trend towards sentence case: Recently, sentence case capitalization (only capitalizing the first word) has grown popular for its casual and conversational tone.
  • Email trends: Many popular brands, such as Fast Company, have adopted sentence case in their email marketing campaigns.

In conclusion, testing different approaches with your audience can reveal what works best.

Tools and Tips for Capitalizing Your Subject Lines

  • Always capitalize the first word in your subject line.
  • Capitalize all proper nouns.
  • For a more casual tone, consider using sentence case.
  • Avoid using all caps as it can trigger spam filters.
  • Use a style guide or tool to ensure consistency.
  • Limit subject line length to 50 characters.
  • Test different styles to see which increases open rates.
  • Personalize subject lines with the recipient’s name to increase open rates.


Proper capitalization of email subject lines is essential for catching the recipients’ attention and improving open rates. Capitalization consistency showcases professionalism and brand identity.

By personalizing subject lines and avoiding spam triggers, email marketing strategies can significantly improve. It’s crucial for marketers to consider capitalization’s impact on their email campaigns and capitalize their subject lines strategically.


  1. What is the best practice for capitalizing email subject lines?
    Best practice involves using sentence case capitalization, where you only capitalize the first letter and any proper nouns.
  2. Does capitalizing every word in your email subjects help with open rates?
    No, a good subject line that resonates with the reader leads to higher open rates instead of just upper case or lowercase letters.
  3. Is there an issue with using all caps in your subject line?
    Yes, all caps may trigger spam filters causing emails to land in spam folders rather than the inbox.
  4. How does lower case in email subjects impact my marketing strategy?
    Lowercase subject lines create a casual tone, which might work well depending on your audience and content. However, there’s no one-size-fits-all solution as it depends on various factors, for example, the type of business and the product being marketed.
  5. Can poor capitalization affect my email deliverability?
    Yes, incorrect usage of capital letters could flag your emails as spam, affecting deliverability and response rates. We recommend integrating multichannel marketing with MarTech stack tools to improve your results.
  6. Are there any automation tools that can help with proper capitalization?
    Yes, many email automation tools provide options for sentence case or other styles, ensuring proper etiquette and helping grow businesses by enhancing their overall email marketing strategy effectiveness.

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