How do you write subject lines that cut through the noise?

With the average person now receiving 125 business emails every day, it’s hard to get your email to stand out from the crowd. Even if you’ve done everything right up until this point—you’ve segmented your email list, you’ve written compelling copy, and you’ve ditched your HTML template for plain text—you still need to pass one final gatekeeper in order get someone to open (and reply to) your emails: the subject line.

Think of your email subject line as the headline of a news article. It’s your chance to grab someone’s attention and introduce the information that’s coming next. And while it can be tempting to make your subject lines catchy and overblown in order to attract eyeballs, a better option is to keep your subject line anchored in reality and in the actual content you’re sharing. Remember: your goal here isn’t to drive clicks, it’s to start conversations. If the content of your email doesn’t line up with what you promised in the subject line, people aren’t going to have a good experience.

The solution, of course, is simple: Avoid hyperbole. And don’t try to trick people into opening your emails. Instead, you should focus your energy on writing subject lines that are relevant to your different segments, and that can succinctly address how whatever it is you’re sharing or promoting in your email can help people solve actual problems and address industry-specific needs.

In our email study, we found that the best-performing emails tend to have subject lines that are between three and six words long. However, that’s not a hard and fast rule, as there were plenty of high-performing emails that had much longer subject lines. Ultimately, in order to figure out the types (and lengths) of subject lines that work or don’t work for your business, you’re going to need to test, and test, and test some more. You can also use free tools, like the Send Check It email subject line tester, to see how your subject lines stack up against thousands of others based on attributes like scannability, length, and sentiment.


 Divide your email list in half. Send an email to the first half (Group A) using one subject line and then send that same email to the second half (Group B) using a different subject line. For example, you could test…

  • long subject line vs. short subject line
  • statement vs. question
  • capital letters vs. lowercase letters

Which types of subject lines gets more replies?


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