E-commerce
September 17, 2026
Wondering if special characters in email subject lines can boost your open rates? The answer is: yes, sometimes, but with caution. These small symbols, hearts, arrows, stars, are not just simple decorations: they can capture attention, reinforce your call to action, and even improve engagement, provided you use them wisely.
Be careful though: if used poorly, they can harm deliverability or give a spammy impression. Their effectiveness varies depending on the context, the sector, and the perceived novelty. So, how can you take advantage of special characters without falling into the traps? On the agenda:
Why do special characters sometimes work so well?
What are the risks for deliverability and brand image?
How to choose the right symbol for your audience?
What mistakes must you absolutely avoid in your email subject lines?
How can Qstomy help you optimize your campaigns?
Let's go.
Summary
Why do special characters catch the eye in an inbox?
In a saturated inbox, every detail counts to stand out. Special characters, such as ♥, ✈ or ☂, act as immediate visual signals. They break the monotony of the text and create a focal point that catches the eye even before the message is read.
Their effectiveness is based on contrast: a well-chosen symbol, related to your offer, reinforces the message and makes you want to know more. For example, a right arrow can suggest action, while a heart evokes affection or loyalty. It is a universal language that goes beyond words.
But beware: the surprise effect fades with repetition. What worked a year ago may seem outdated today. The important thing is to use them sparingly and with relevance, as shown by Penton Marketing's tests where a subject line with special characters largely outperformed others in opens, clicks, and sign-ups.
Finally, remember that the goal is not to shock, but to seduce. A subtle and elegant symbol can have more impact than a garish emoji. Test different approaches to find the style that fits your brand and audience.
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What are the risks to deliverability and brand image?
Special characters are not without risk. Spam filters have long associated these symbols with fraudulent practices because spammers used them extensively to bypass filters. As a result, some email clients may classify your emails as spam if you overuse symbols.
The risk is real, but nuanced. Tests show that the impact depends on the symbol used, its frequency, and the industry. For example, stars at the beginning and end of subject lines are common among some retailers, but that does not mean they always pass through filters.
To minimize risks, test your campaigns on different email clients and monitor your deliverability rates. If you notice a drop, reduce the use of special characters or vary them. The goal is to capture attention without triggering alarms.
It is also wise to consult the recommendations of your email service provider (ESP) and follow industry best practices. Regular monitoring will allow you to anticipate changes in filters and adapt your strategy accordingly.
How do special characters influence engagement beyond opens?
The impact of special characters is not limited to open rates. They can also influence overall engagement: clicks, shares, and even the perception of your brand. Case studies, such as those from BeNaughty.com and Voyage Privé, show that emails with symbols are less frequently marked as spam and more often forwarded.
This is explained by the "nudge effect": an email that is seen but not clicked can prompt the recipient to visit your site within 24 hours. The symbol acts as a subtle advertisement that sets the stage.
Thus, even without an immediate click, a special character can contribute to brand recall and a subsequent visit. It is a subtle but powerful lever to strengthen loyalty and long-term conversion.
To maximize this effect, combine the symbol with a clear message and an attractive offer. A symbol alone is not enough: it must be integrated into an overall strategy that inspires action.
Which symbols offer the best open rates?
Not all special characters are created equal. CheetahMail, an email service provider, analyzed data from numerous brands and found significant variations: the heart (♥) is the most popular symbol, but it offers only a modest 2.2% increase in opens. In contrast, the black sun with rays generated a 14.9% increase, and the airplane (✈) 10.7%.
Most surprising: the umbrella (☂) produced a dramatic 50% increase in unique opens. This shows that less common symbols can have a "wow" effect and capture more attention.
Lesson: don't just settle for the most widely used symbols. Test original variations, related to your industry or your message, to maximize impact. Originality can be your ally.
However, keep in mind that a symbol's effectiveness can vary across cultures and markets. What works in one country may not have the same effect elsewhere. Adapt your choices to your target audience.
How to choose a symbol related to your message?
A special character is not a simple decoration: it must reinforce the meaning of your message. In the Penton Marketing test, the winning subject line used symbols that directly supported the call to action. The medium was the message, not a superficial addition.
For example, an arrow pointing to a discount offer is more relevant than a heart for a promotional email. An inconsistent symbol can confuse the reader and harm your brand's credibility.
Before adding a symbol, ask yourself: "Does this clarify or reinforce my message?" If the answer is no, leave it out. Relevance is key to avoiding a gimmick effect.
Also, consider consistency with your visual identity. A symbol that recalls your logo or your colors can strengthen brand recognition and create a stronger emotional connection.
What is the golden rule for moderate use?
The golden rule is moderation: only one special character per subject line, maximum two. Examples that work, such as those from ModCloth or the "bookend" stars from Think Fast Toys, rarely use more than two symbols.
Too many symbols can look garish or spammy, and dilute the impact of each one. The eye needs a focal point, not a riot of signs.
If you want to test multiple symbols, run A/B tests to measure the effect on your open and click-through rates. You will find the right balance for your audience.
Don't forget that the length of the subject line also matters. A subject line that is too long with symbols may be truncated on mobile. Keep it concise and punchy.
Which errors should you absolutely avoid in your email subject lines?
The main pitfall is excessive or inappropriate use. Symbols that do not match your brand image can damage your credibility. For example, a festive symbol for a luxury brand may seem out of place.
Another pitfall is neglecting compatibility: some characters may not display correctly on all devices or email clients, resulting in a broken rendering.
Finally, do not systematically copy competitors. If everyone is using stars, your email will go unnoticed. Look for originality while remaining consistent with your identity.
To avoid these pitfalls, establish a usage guide for special characters within your marketing team. Define the authorized symbols, their frequency, and the contexts of use. This will ensure maximum consistency and effectiveness.
How to test the effectiveness of special characters?
To find out if special characters work for your audience, nothing beats an A/B test. Create two versions of the same email: one with a symbol, the other without. Send each version to a representative sample and compare open, click, and conversion rates.
Also test different symbols to identify those that resonate most with your subscribers. Data from CheetahMail shows that less common symbols can deliver surprising gains.
Don't forget to measure the long-term impact: a symbol can lose its effectiveness over time. Refresh your tests regularly to stay relevant.
Ensure your tests are statistically significant by using a sufficient sample size. Rigorous analysis will allow you to make informed decisions and continuously optimize your campaigns.
What are some examples of brands that successfully use special characters?
Several brands have successfully integrated special characters. ModCloth, for example, used symbols to creatively reinforce a message while respecting the brand's spirit. Think Fast Toys, Ulla Popken, and BBOS regularly use stars at the beginning and end of subject lines, a "bookending" technique that seems to work for them.
These examples show that repetition can pay off if the symbol is associated with a strong identity. Customers eventually associate the symbol with the brand, which reinforces recognition.
However, what works for one brand does not necessarily work for another. Analyze your audience and test to find your own style.
Draw inspiration from these examples, but do not copy them blindly. Adapt them to your sector, your tone, and your objectives. Authenticity is essential for building a relationship of trust with your subscribers.
How to integrate special characters into a global strategy?
Special characters should not be used in isolation. They fit into a broader strategy that includes segmentation, timing, and personalization. A relevant symbol can reinforce the impact of a well-targeted offer, but it is no substitute for good segmentation.
For example, for a loyalty campaign, a heart symbol can evoke the customer relationship, while an arrow can guide towards a specific action. Combine them with clear subject lines and strong calls to action.
Don't forget that email marketing is a complementary channel to other levers like SMS or notifications. A consistent omnichannel approach maximizes the impact of each message.
Finally, take into account your customers' lifecycle. A symbol can be more effective for a new subscriber than for a loyal customer. Adapt your strategy based on the maturity of the relationship.
How can Qstomy help you optimize your campaigns?
Qstomy, the Shopify AI agent, supports you in customer loyalty and conversion through personalized recommendations, upsell and cross-sell suggestions, and integrated parcel tracking. Although Qstomy does not directly create your email subject lines, it helps you understand your customers' behavior to better target your messages.
By analyzing browsing and purchasing data, Qstomy identifies the opportune moments to send your emails or SMS, and can even suggest complementary products to highlight. This allows you to personalize your campaigns and increase their relevance, making your special characters even more effective.
Additionally, Qstomy simplifies customer service and inquiry management, freeing up time to refine your marketing strategy. With over 100 merchants supported, Qstomy is a valuable ally in turning your visitors into loyal customers.
By integrating Qstomy into your stack, you benefit from a 360-degree view of your customers, allowing you to create more relevant campaigns and improve your return on investment.
Final checklist before sending your emails
Before clicking "send", check these points:
Relevance: Is the symbol directly related to your message?
Moderation: Are you using one or two symbols maximum?
Compatibility: Does the symbol display correctly on major email clients?
A/B Testing: Have you compared with a version without symbols?
Deliverability: Are you monitoring your spam and bounce rates?
In short: Special characters can be an asset, but they require strategy. Use them sparingly, test, and stay tuned to your audience.
FAQ: Are special characters considered spam?
Not systematically, but excessive use can trigger filters. Keep it moderate and test.
What is the best symbol for a loyalty email?
The heart is popular, but an original symbol like the umbrella can surprise and perform better. Test.
Do special characters work on mobile?
Yes, but check the rendering on different screen sizes to avoid truncations.
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Enzo
September 17, 2026
