Your customers’ email inboxes are as crowded as a New York sidewalk, and the biggest bit of real estate you get to grab their attention and convince them to open your marketing message is the subject line, maybe 50 characters max.

Here are five tips to help you write the best email subject lines and win the click:

1. The First Rule: There Are No Rules, Just Measurement

Long or short, funny or serious, all that matters is what types of subject lines get results with your particular audiences. In email marketing, it’s easy to measure success: how many subscribers open a message, how many go on to click something in the message, and ultimately convert to customers. Also, your email service should provide an easy way to test one subject line vs. another on segments of your audience before you send it to the whole list. Worth doing, though the results won’t always be definitive.

2. The “From” Line Is Part of the Subject Line, Mentally

Email users see both and weigh both in deciding whether to open the message. “From” could actually be more important at times. Consider this: Barack Obama raised millions for his 2012 re-election on email campaigns with subject lines like “Hey” and “Wow” because his “brand” was so strong with his supporters. A large part of the effect of your subject lines will be determined by how likable you’ve made your brand and the expectations your previous email messages set for value delivered.

3.  Tell, Don’t Sell

“The best subject lines tell what’s inside, the worst ones sell what’s inside,” email vendor MailChimp concluded after a study in which straightforward lines (like this snoozer: “Preliminary Floor Plans for Southern Village Neighborhood Circle Members”) consistently beat on open rates hyper-ventilating, sales-y wording (like “SALE ends soon – up to 50% off all bras at Kara!”). Why? Because they promised a specific value for the click that was relevant and timely for the customer--and they seemed likely to deliver the value, not the hype.

4.  The Lengthy Debate about Length

For years, email marketers split on whether shorter (say 4-15 characters) beat longer (like 50 or more characters) and cited studies of open rates one way or the other. The consensus in the business seems to have settled down to: It doesn’t matter. But know the physical limits. On a desktop computer, an inbox displays about 60 characters of the subject, on a mobile device, just 25-30 characters.


Email marketers have used capitalization, punctuation, hot button words (“call now!”), and recently emojis to make subject lines stand out. Just be cautious here. Email service providers (Yahoo Mail, Gmail, etc.) run spam filters behind the scenes that check subject lines and a long list of other factors you’ll never know to decide whether to block your messages or let them pass.  Anyway, users are wary of spammy-looking pitches. The best defense is to keep your subject line consistent with your brand and the content of your email message, and not try to win the click by waving bright, shiny objects at your subscribers.

Learn more about email subject lines and why your customers don’t read your marketing emails on the Thryv blog.

About the Author(s)

 Jeff B. Copeland

Jeff B. Copeland is the senior product manager for content at Dex Media, the digital marketing experts for local businesses. Read more of his writing on the Dex Media Blog.

Senior Product Manager, Dex Media
Close up of person scrolling through emails on their phone