The Importance of Engaging Subject Lines and Preheaders for your Emails

Testing each component of your email should be part of every campaign. Two make-it-or-break-it elements in terms of open rate and engagement are the subject line and the preheader. Even if a reader is predisposed to open emails from you, the subject line and the preheader usually determine whether a particular email gets opened or not. The preheader is the text that is visible beneath the subject line when an email is previewed, particularly on a mobile device.

Most of us receive more than 100 business-related emails each business day. We scan our inboxes and triage our way through the list. We open and respond to the most urgent and skip, delete, and file the remainder for later attention. The subject line is most critical here. It often determines whether your email gets opened and should receive your best creative attention. Here are some proven subject line strategies to increase your open rate:

  • “How to” promises the reader practical knowledge
  • Short subject lines are more inviting—particularly for mobile consumption
  • Call to action—conveying a sense of urgency
  • Topical—news or trending topics
  • Humorous—tricky to pull off but when done right can be very effective
  • Personalized— best when there is a real relationship with the reader

Some of the worn-out, tired subject lines use typographical tricks such as all caps or excessive symbols. By the way, most spam filters are programmed to reject emails with these in their subject lines.

A new report from Adestra on the effectiveness of subject lines is now available. This study reviewed millions of emails across multiple industries, so their results may vary slightly depending on the specific market. However, there is a lot here to apply to the education market.

The 10 Best Performing Words in Email Subject Lines

Thank You 62% Golden 32%
Monthly 47% *|*|*| 32%
*|*|*|*| 47% iPhone 30%
Thanks 34% Breaking 27%
Bulletin 32% Order Today 27%

The 10 Worst Performing Words in Email Subject Lines

Subscription -28% Learn -36%
Early Bird -29% Whitepaper -40%
Industry -30% Training -47%
Report -32% Forecast -47%
Intelligence -35% Journal -50%


The complete 2015 subject line analysis report from Adestra can be found here.

Living in a Mobile World

Although expert estimates vary slightly, the consensus is that more than 50% of emails are now read on mobile devices. That percentage is expected to increase as mobile devices continue to lead the pack in Internet connections. When previewing email on a smartphone or other mobile device, the preheader text falls beneath the subject line of an email and refers to the top two to three lines of visible text.

Repeating the subject line here is wasted space. A compelling preheader is an additional opportunity to engage the reader before they decide to open or delete the email. Sometimes the split moment decision to open is made on the quality of the subject line only; sometimes it’s made in conjunction with the preheader.

While you can use the preheader to highlight a different offer than what is promised in the subject line, more often successful preheaders are used to extend the story or promise of the subject line by providing:

  • More context
  • More details
  • Personalization
  • An offer

The subject line and the preheader are two of the most important elements of successful marketing emails. You can’t assume that because someone is a customer that they will open your emails. Invest the time you need to create and test these key elements so that your email marketing remains effective.

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