Experts estimate that 361.6 billion emails are sent everyday worldwide. That’s not a typo. And it’s still climbing. By 2027, we’re looking at over 408 billion emails a day (Email Tool Tester). So if you’re wondering why your latest campaign didn’t get the love it deserved, that’s why.

Inboxes are busier than ever. To stand out, your subject lines need to do more than announce a message. They need to earn a click.

Let’s explore the strategies that continue to work in 2025, backed by fresh insights and practical examples. 

Personalization That Feels Personal 

Subject lines that include a name or refer to a specific user action tend to perform better. According to new data, personalized subject lines increase open rates by 7.4%, and often lead to 6 times more transactions (MoEngage). However, personalization isn’t just about first names. It’s about timing, context, and relevance. 

Examples:

• You Left This Behind 
• Still thinking about [product name]?
• Your monthly summary is ready

At PIXL, we’ve noticed that in real estate email campaigns, plain subject lines like Available Now: Downtown 2BR Unites consistently outperform anything with excessive personalization. Context and clarity win. 

Urgency That Isn’t Screaming 

A well-placed nudge can move your reader to action, especially when time is limited. When currency is done right, it triggers attention without pressure. Avoid loud tricks like ALL CAPS or five exclamation points. Instead, use clarity and timing.  

Examples:

• Sale ends tonight
• Just for you, until midnight
• Last 12 hours to register

Avoid Spam Triggers

Almost 49% of emails people receive daily are flagged as spam (Email Tool Tester). Many don’t even make it to the inbox. What triggers filters? Words like Free, Act Now, or Make Money, excessive symbols, and deceptive formatting. Keep it clean, clear, and real. 

Use of Numbers

Numbers break the visual monotony in an inbox. They offer structure and a promise of quick value. Subject lines with numbers perform especially well when the email body supports the claim.

Examples:

• 5 features to look for in your next property
• 3 mistakes to avoid when investing 
• 7 questions clients ask before they buy

Don’t Waste the Preview Text

The preview line is your second chance. If you leave it blank, most platforms will pull in the first line of your email, which is rarely optimized. Write it with purpose. Think of it as a companion to your subject line, not a repeat. 

Examples:

Subject: The Villas You Asked For Are Live

Preview: Starting from AED 1.1M, with flexible payment plans

Test, Review, Repeat

Every audience reacts differently. A/B testing remains one of the most effective ways to find what works. Test not just your subject lines, but also send times and frequencies. For instance, 2025 report shows that email open rates differ drastically by industry. Retails sits around 33.57%, while childcare and community services exceed 43% (Email Tool Tester).

Email Length and Behavior

The average email contains around 434 words (AWeber), but readers often skim. If the subject line piques interest, the body needs to hold it. Make the connection between the two seamless and worth the reader’s time.

Final Thoughts

The perfect subject line doesn’t need to be clever or quirky. It just needs to be clear, timely, and relevant to the person receiving it.At PIXL, we’ve seen that small tweaks in language or send time can move open rates from average to exceptional, especially when the strategy matches the segment.

Still unsure what your audience will respond to?

At PIXL, we’re happy to help you test, fine-tune, and deliver emails that don’t go unnoticed.