Your emails called. They want a subject line makeover.
AI, emojis, voice tech – everything you need to know about new-age subject lines.
Hey there,
What worked in email marketing yesterday might flop today. Inbox algorithms are shifting. User behavior is changing. If you’re not evolving, you’re slowly vanishing from view.
Because staying current = staying relevant.
That’s why today, we’re zooming in on one thing that’s quietly transformed in recent times: Your subject line.
We’ve rounded up 5 essential rules to help you update yours for today’s audience. And if you’re looking for a shortcut, RetainIQ has you covered.
Book a free consultation today
Here’s what you need to know:
1. Subject lines are solo acts now – forget the preheader assist.
For close to two decades, subject lines and preheaders were a package deal. One could play off the other, and together they could take your email marketing to the next level.
Not so any more.
With two of the largest inbox providers – Google and Apple – implementing updates, things have changed drastically:
Google replaces some promotional emails’ preview text with Deal Annotations, which the inbox provider automatically applies.
Apple Mail’s inbox replaces sender-written preview text with its own AI Summaries.
These changes make it risky or outright problematic to write subject lines that rely on the preheader for clarification. Your subject line needs to make sense on its own – no tag-team play anymore.
2. Generic is out – context-driven subject lines win.
Today’s inboxes are crowded. Stand out by making your emails feel like they were written just for the reader. Contextual triggers like purchase confirmations, browsing history, or product interests can transform a generic “Thanks for your order” into “Hope you love your new XBox, Sarah!”
3. Use AI – but don’t hand over the wheel.
Machine Learning (ML) and Artificial Intelligence (AI) can help you craft interesting subject lines, but you need to know what you're working with.
ML tools like Persado and Jacquard can generate subject line suggestions based on past email performance data. However, many marketers find their output clickbaity, short-lived in impact, and not cost-effective.
Generative AI tools (like ChatGPT) are better for idea generation, brainstorming, and editing. However, they are not as great for performance boosts. They don’t factor in past performance or audience data, so results depend on how marketers use them. For best outcomes, use generative AI as a creative assistant and always test subject lines thoroughly.
4. Subject lines could include visual elements.
The first thing to decide is whether emojis are on-brand for you as they often present a casual or cutesy vibe. If you decide to opt for them, the next thing to do is to create a few usage guidelines. Create a list of emojis that work for your brand, carefully excluding NSFW ones. Think no eggplants and peaches. You could use this sheet we’ve created for quick use.
Also check Emojipedia to understand the variations in how emoji are rendered across platforms.
Finally, establish rules for emoji placement. They usually look best at the start or end of a sentence. However, you could place them in between as a separator between two ideas. That said, NEVER use them as a replacement for words – only use them to complement ideas.
5. Make your subject lines voice-friendly.
The challenging part about writing subject lines today is that in addition to being more visual, they also need to be more auditory. As using screen readers and voice assistants increasingly becomes the norm, this is a trend that you’ve got to keep up with.
Some things you want to be very careful with in case you are using them include:
Emojis
Onomatopoeia
Air quotes
Parenthesis
Strikethroughs
Abbreviations and acronyms
Conclusion
Subject lines have always been a first impression. But now, they’re your only chance to hook attention. Use these changes as an opportunity to refresh your approach and keep your emails performing at their peak.
Need help leveling up your subject lines – or your entire email strategy?