law firm content marketing

A Legal Marketer’s Guide to Writing Email Subject Lines that Boost Open Rates

by Guy Alvarez • December 13th, 2022 • Content Marketing | Blog

Subject lines are a make-it or break-it element of email marketing. The average inbox sees more than 100 emails per day. How do people decide what they’re going to open and what they’re going to immediately delete? A compelling email subject line. Keep reading to learn how to make your best first impression when it comes to email. 

1. Keep it Short and Sweet

This is long-standing advice that never really changes. Many people open emails on a mobile device that cuts off lengthy subject lines (most mobile views show less than 45 characters of a subject line). A Marketo study found that the highest average click-to-open rate (CTOR) happened with seven-word subject lines.

2. Place the Most Important Words at the Beginning

Since most people read email on their smartphones, it’s important to put the most important information at the beginning. Otherwise, compelling details could get cut off. 

3. Eliminate Filler Words

With such precious space, don’t waste it with unnecessary words like “hello,” “nice to meet you,” and “thanks,” which can easily be included in the email’s body. 

4. Don’t Shout at People Using Subject Lines

Using all caps to grab attention can be annoying and can even get your firm flagged as spam. All caps should never be used, and you should test which case – sentence, title, or lower – resonates best with your readers. 

5. Convey a Sense of Urgency

If time is a factor, use phrases like the following in your email subject lines: Act Now! Limited Time Offer! Your Last Chance!

6. A/B Test

A/B testing is highly recommended for email marketing. Try testing out subtle changes in your subject line with real-time A/B testing. Send out two subject lines to 40% of your contacts (split 20/20). The email with the higher open rate will determine which subject line to use when sending to the remaining 60%.

7. Pique Curiosity

Asking a question in the subject line is a good way to do this. What’s the first thing to do if you’re in an auto accident? Do you really need uninsured and underinsured motorist coverage?

8. Include Numbers

Experts say that our brains are attracted to numbers because they help us to organize information in a logical way. Research has shown that small, odd-numbered digits are more compelling to us.

9. Stand Out in the Inbox With Emojis

Over the past decade, there has been conflicting research on using emojis in email subject lines. Some analyses have said they can prompt a higher open rate, but other studies say they can have a negative effect. Before including them, make sure they’re relevant and add to your message rather than a distraction. If you choose to include them, place them at the end or in the preview text. Most importantly, test! You never know if they’ll work for your firm and your particular emails unless you try – but make informed decisions by testing and then optimizing. 

10. Use Logical Keywords for Search and Filtering

Most professionals have filters and folders set up to manage their email, and probably won’t focus on your message when they first see it. That’s why it’s important to include keywords related to the topic of the email that will make it searchable later. 

11. Use Preview Text in a Smart Way

If your email subject line is concise, you can really use the pre-header or preview text to your advantage. For example, your subject line might only have about 25 characters, but the preview text that will display along with it can be just as impactful at 68 characters. It’s important not to just repeat the subject line, though. Add an explanation or highlight details about the email that the subject line didn’t reveal. Grab attention with the subject line and then use the preview text to further convince. 

12. Add Personalization

Personalization has been proven to boost open rates. Including a contact’s name or the name of their company is a simple way to make your email seem less like a mass marketing email and more like a personal send.

13. Use Buzzwords

There are certain words that tend to catch people’s attention. Try using powerful language that will evoke a reaction, such as simple, easy, new, update, latest, alert, etc.  When trying a new buzzword, be sure to pay attention to open rates and deliverability rates before using it again.

14. Avoid Spam Language

Just as you should include buzzwords, there are also certain words that could send your email directly to the spam folder. A big contributor to this is the word ‘free’. 

15. Make it Educational

People will want to open your email if they feel it includes valuable information. Try using sentence structures that convey the educational value of your content. Example: How to File a Lawsuit with Ease.


It’s up to you to constantly test and optimize in order to develop your smartest email subject lines. However, keeping these best practices in mind will provide a good head start when creating high-performing subject lines.

If you need assistance with your law firm’s email marketing strategy, don’t hesitate to reach out to us. We can help you increase the return on investment (ROI) of your email efforts.

This post has been edited and republished from Sep. 14, 2021.


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