7 Ways to Improve Your Email Subject Lines [Infographic]

Subject lines are vital to the success of email campaigns—nearly half of consumers say they decide whether or not to open a message based primarily on its subject line.

However, despite this importance, brands often struggle to improve the performance of their subject lines. All too frequently, marketers aren’t sure which changes to make or even where to start.

To learn how to boost the effectiveness of your email campaigns, check out MDG’s informative infographic, 7 Ways to Improve Your Email Subject Lines.


1. Don’t Be Spammy
No matter how well written they are, subject lines are failures if they lead to messages ending up in junk mail folders. So, it’s essential to first focus on avoiding words and approaches that trigger filters.

Some of the terms that have traditionally been flagged by email service providers’ spam filters are:








Make money



These aren’t the only problematic words, nor are they always triggers—today’s spam filters are sophisticated and evolving. Rather, these terms highlight a general approach that marketers should take: if your subject line is coming across as even slightly spammy or sleazy, absolutely avoid using it.

2. Convey Urgency and Action
Consumers have limited time and a flood of messages arriving in their inboxes. That’s why it helps to convey urgency and to use action words in your subject lines: it motivates people to click immediately.

Some of the terms in subject lines that convey urgency/action and correlate to high open rates are:




Still time

Today only






These are just the tip of the iceberg. There are many other terms that can be used to convey action and timeliness. The challenge for brands is to walk a fine line and find powerful language that sparks action without crossing into the world of spammy subject lines.

3. Add Personalization
How can you ensure that your messages will stand out in consumers’ inboxes? One of the most effective tactics is to add elements of personalization to your subject lines.

While its impact varies depending on execution, personalization broadly tends to improve performance:

  • Multi-channel retailers have seen open rates increase by as much as 37% when adding personalization to subject lines.
  • Overall, subject lines that include the first name of the recipient have a higher average click-through rate compared with those that don’t.

This doesn’t mean that personalization always improves campaigns. To be effective, it’s essential for the tactic to be well thought out and well executed. The personalization elements must be based on correct data and truly individualized without coming across as being targeted in a creepy way.

4. Be Mindful of Mobile and Length
The ideal subject line length is hotly debated topic. For years, arguments have been made for various character counts. However, the scales recently have tipped in favor of shorter because of mobile.

Most messages are now seen on devices that display a small number of subject line characters:

  • More than half of all emails are opened on mobile devices.
  • Most emails on smartphones show between 27 and 64 characters of a subject line.

Marketers should keep these limitations in mind when creating campaigns. Increasingly, subject lines longer than around seven words aren’t displayed in full to recipients. And, as consumer behavior continues to shift toward mobile, the importance of keeping things short and sweet should only grow.

5. Experiment with Numbers and Emojis
If you want your email campaigns to stand out, one approach is to mix things up: try branching out beyond letters and experiment with using numbers and emojis in your subject lines.

Numbers, especially lists, tend to work well across digital, and email is no exception:

  • Email subject lines that include a number have a higher average open rate and higher average reply rate compared with those that do not.

Emojis are more of a mixed bag. Their impact tends depend which emojis are used and on the context:

This shifting effectiveness highlights that numbers and emojis aren’t silver bullets: they help sometimes and hurt sometimes. Moreover, how many are used in a subject line can influence the impact. For marketers, then, the key is use them smartly and sparingly.

6. Care About Capitalization and Punctuation
Two more things that brands can experiment with are capitalization and punctuation. Each can also affect the performance of a campaign, though discerning what works and what doesn’t takes some time.

Capitalization/case has been shown to influence engagement in various ways:

  • One study found that capitalizing only the first word in subject line results in a higher average open rate.
  • A different study found that using all lowercase letters in subject lines results in a higher average open rate.

Similarly, punctuation has been shown to influence engagement. Studies have found:

  • A single period can boost open rates, but more than one can hurt.
  • Question marks can sometimes drop click-through rates.
  • Exclamation points can sometimes increase open rates.

What should marketers make of all this? The first takeaway is that it’s clear that consumers notice capitalization and punctuation in email subject lines. The second is that brands should be wary of hard-and-fast rules: the impact of capitalization and personalization depends largely on the context.

7. Focus on the “From”
When thinking about subject lines, marketers usually concentrate much more on the “what” than the “who.” This is a mistake because the “From” field is an integral part of any successful campaign.

Consumers pay close attention to who sends the emails that arrive in their inboxes:

  • 64% of people say they decide which emails to open based solely on who they come from.
  • 43% of people say they’ll mark a message as spam based on the info they see in the “From” field.

The keys here are trust and familiarity—consumers need to feel comfortable before opening a message. That’s why it’s important to avoid sending campaigns from addresses that are confusing and/or that are coldly corporate. Instead, use names and addresses that clearly convey who the email is coming from.

Of course, it’s impossible to say exactly which address you should send from, just as it’s impossible to say which words you should use or how you should punctuate. To do that, it’s essential to test, test, and test some more.

Ultimately, that’s the secret to subject line success: pair the tactics covered here with an ongoing, well-thought-out testing program to find the right approach for your brand.

To find out more, check out our full infographic, 7 Ways to Improve Your Email Subject Lines.

7 Ways To Improve Your Email Subject Lines Infographic

Learn more about the power of subject lines in email marketing. Contact MDG today at 561-338-7797 or visit www.mdgsolutions.com.

MDG, a full-service advertising agency with offices in Boca Raton and Brooklyn, NY, is one of Florida’s top branding firms. MDG’s capabilities include print advertising, direct mail marketing, branding, logo design, creative, media buying and planning, radio and TV advertising, outdoor, newspaper, digital marketing, website design and development, online video advertising, infographic development, email marketing, video marketing, mobile marketing, content marketing, social media marketing, paid search marketing, and SEO. To learn about the latest trends in advertising and branding, contact MDG today at 561-338-7797 or visit www.mdgsolutions.com.