The Orchard Agency, Melbourne Australia, eCommerce Email Marketing Specialist Agency


Subject Line Symbols for Email

Incorporating subject line symbols (such as a ❤ or a ☺) into an email campaign is a great way for your email to stand out from the pack.

However, a lot of marketers are apprehensive about using subject line symbols due to the issues associated with email-browser compatibility.

This is a valid concern and the purpose of this article is to shed some light on this topic and provide clarity on both the effectiveness and compatibility of subject line symbols.  

Subject line symbol compatibility

In an ideal world, there would be a definitive list of symbols that marketers could use.

According to Experian, email clients use different font sets and understand different encoding methods, therefore there are millions of possible permutations of symbols that will render and not render. For example, while a black sun (☀) might exist in the font encoding set used by Gmail viewed through Chrome, it might not exist in the font and encoding set used by a BlackBerry. As you can see, a definitive list is simply not possible.

However, support for symbols outside of the standard character set is surprisingly good across email browsers.

Apart from Outlook 2003 (which is a decade old) and Lotus notes, there is near universal support to add special characters into the subject region. Certain platforms such as Hotmail/ and iOS devices can even convert certain symbols like a ❤ into “emoji” or a small graphic, such as:

Below is a list of popular email platforms that support subject line symbols. However, be careful as some symbols aren’t universally supported, so testing is crucial!

Email PlatformSymbol Support
Outlook 2007, 2010, 2013Yes
Outlook 2003No
iPhone / iPad (iOS)Yes
Apple MailYes
Yahoo! MailYes
Windows MailYes
Android MailYes
Lotus NotesNo

If you communicate primarily to a B2C audience, the fact that Outlook 2003 and Lotus Notes do not support subject line symbols should not concern you. According to Litmus, the two email-browsers in question do not even factor in the Top 10 email platforms in terms of usage.  

Test, test, test…

As mentioned before, there is no definitive list of compatible subject line symbols. Therefore, testing your subject line is paramount. A great tool to test your emails is  Litmus. Litmus provides the ability to see how your subject lines render on top of how sound your email code is.  

Engagement enhancements with subject line symbols

There seems to be evidence that subject line symbols can provide improvements in audience engagement. The guys at Experian indicated that subject lines with symbols had a higher unique open rate in 56% of brands they analysed.

Below are some more of their findings regarding usage of symbols:

  • The black heart (♥) is the most popular symbol, but provided only an open rate lift of 2.2%
  • Of the 5 most popular symbols, the black sun with rays had the highest lift in open rates (14.9%)
  • Airplanes (✈) had a 10.7% lift in unique open rates, while umbrellas (☂) generated a 50% lift

Over at Litmus, they’ve seen anecdotal evidence suggesting that open rates are about 10-15% higher for emails that used a symbol in the subject line.

Even without metrics, one can understand why symbols might generate an uplift in open rates. Symbols in the subject line help generate better visibility within the inbox and in an age where email is becoming an increasingly more popular way to communicate/market, any technique to generate better engagement is an invaluable tool.

Using subject line symbols

Inserting a symbol into a subject line is as simple as copying from a source and pasting it into the area where you enter in your subject line. Below are some sources you can use to implement symbols into your own emails:

When to use subject line symbols

The rule of thumb regarding symbols in subject lines is relevancy and sparingly. Symbols are a great way to make your email stand out from other emails in the inbox, but don’t over do it. It’s also important to select the right symbol based upon your content. Remember the subject line is a description of the email and in order to establish trust with your audience, your subject line should reflect the contents inside.


Found this helpful? Check these related articles out