Truss Logo White
Truss Mailbag

Subject line rewrite

Our beginners guide to subject line best practices.

The Personalized Subject Line

In the world of email marketing, a great subject line is a holy grail. Why all the fuss over these 40 +/- characters of carefully crafted copy? The TL;DR version: if your subject line misses the mark, your email is dead on arrival.


  • 47% of email recipients will open your email based solely on the subject line—OptinMonster
  • 69% of email recipients report email as spam based solely on the subject line—OptinMonster
  • The average email open rate for all industries is just 21.33%—Mailchimp

Despite this, email marketing is a proven and efficient channel for your marketing messages. In fact the Direct Marketing Association reports that for every $1 spent, email delivers an average ROI of $32 across all industries (via Sale Cycle).

It literally pays to master the subject line.

To get us closer, we thought it’d be fun to play a game of “subject line rewrite.” We went into our inbox to scavenge for trashed and unopened emails that could have enjoyed a different fate with a better subject line. While this is a completely subjective evaluation,—we have no commercial relationship with these brands and have zero access to the performance analytics of the emails featured here—our goal is to highlight how subject line best practices can be applied to real emails to improve email marketing performance.

The Personalized Subject Line

Emails with personalized subject lines are 26% more likely to be opened. Including the name of your recipient in an email subject line is the low hanging fruit of personalization. With a little bit of list hygiene and diligence, it could be a great way to drive sluggish open rates. Purchase follow-up emails are an easy and obvious place to try this tactic, but many brands forget this best practice.

Here’s how we would tweak this product review request email from the luxury beauty buyers’ club Beauty Pie using the personalization tactic.

TRUSS SUBJECT LINE: Steph, tell us what you really think?

The Open Loop Subject Line

The Open Loop Subject Line

Open loop subject lines tease you with enough information to pique your interest but leave you wanting more. Posing a question is an easy way to start an open loop conversation with your email audience.

In this example, we’re rewriting a subject line from a barre studio that was hosting a teacher training info. session.

REAL SUBJECT: Barre3 Instructor Recruitment Class
TRUSS SUBJECT: Is this going to be your year?

The FOMO Subject Line

The Fomo Subject Line

Emphasizing the urgency and timeliness of an offer is a tried and tested strategy that works particularly well in email subject lines.

Below, a specialty spirits shop was promoting a virtual daiquiri and rum tasting. Featuring four rare spirits, one of which hadn’t been released on the West Coast, only a few tasting kits were available for purchase. But they didn’t tell us that in the subject line! What a missed opportunity to leverage the limited nature of the offer to raise the urgency. The email also came without a pretext, which is the line of text that comes after the subject line in an inbox.

REAL SUBJECT: Virtual Daiquiris and Exclusive Rum Tasting

TRUSS SUBJECT: Calling all rum nerds! 🥃🤓
PRETEXT: Snag one of 20 tasting kits for West Coast launch of Foursquare 2008 + daiquiri masterclass by Chris Dion.

The Short and Sweet Subject Line

The Short And Sweet Subject Line

A concise subject line is not only weirdly gratifying to write, but also proven to be effective. Research shows that around 41 characters is the optimal length for a subject line. If you can say it in fewer characters, all the better!

Below, GoDaddy’s subject line is problematic to us for a few reasons. Besides plugging a percent off discount (more on that later), it is too wordy for no good reason.

REAL SUBJECT: Revealed: The easier way to create great images + 30% off GoDaddy products

TRUSS SUBJECT: No design skill? No problem.
PRETEXT: Create website graphics in a flash with Over by GoDaddy.

By getting rid of the fluff and the discount message, our version takes it from 74 characters to just 28.

Other tips and tricks to optimize open rates…

Don’t forget your pretext

As you’ve already seen, we are big fans of the email pretext (also known as preheader text). Functionally, it is a blurb that captures the gist of your content. Many email clients will use the first few sentences of an email as the pretext by default. But with a bit more effort, you can customize your pretext to make it an extension of your subject line concept. For instance, your subject line could be the funny or eye-catching headline and your pretext could act as the hardworking subhead, delivering the who, what, where, when, and/or why of your message.

Use your brand name in the From field

This landed in our inbox the other day. The first question that came to mind was, who is Sarah Gibson?

Use Your Brand Name In The From Field@2x

As it turns out Sarah is the owner of a homewares ecommerce shop. We opted-in to receive emails from her store after a purchase more than a year ago and had completely forgotten about it. As a result, we nearly sent Sarah and her oil bottles to the spam folder. The lesson: if you’re a business owner, don’t assume your subscribers know your name. Chances are they are much more familiar with your brand, so make sure to include it in your email From field to avoid getting trashed or flagged as spam.

Develop a subject line formula to stand out from the crowd

If you’re writing a newsletter or other form of consistent email content, coming up with a formula for your subject line could be a great way to visually standout in an inbox. For instance, the content marketing queen Ann Handley styles the subject line for her bi-weekly newsletter, Total Annarchy, the exact same way every time:

TA + {newsletter number}: + emoji + topic list

Develop A Subject Line Formula To Stand Out From The Crowd

Though her subject lines are often long, they work because she applies a consistent formula to them that fans of her writing have come to know and can easily scan for.

Avoid the hard sell

Words such as “free,” “percent off,” and copy that is generally too salesy have been found to negatively impact open rates. Save that language for the content inside the email.

This spam folder screenshot makes the case. Of the brand’s seven flagged emails, 4 of them contained a “free” or “percent off” discount message.

Avoid The Hard Sell

Back to The Angle

Recent posts

Truss' work for homebuilder Thomas James Homes led to Best Overall Advertising Campaign at the 2022 National Sales and Marketing Awards.
What’s so wrong with committing (or recommitting) to better habits, thoughtful actions and new perspectives? These are the 6 things we’re excited to focus on as an agency in the New Year.

Sign up for Wide Angle, our quarterly digest of brand and marketing wisdom.

  • This field is for validation purposes and should be left unchanged.