10 Tips for Writing Subject Lines That Get Opened

10 Tips for Writing Subject Lines That Get Opened

MailBolt
MailBolt™ Team
Author
2025-05-01
Published
3 min read
Reading Time

The Gateway to Your Content

The subject line is the first thing your recipients see. If it doesn't grab their attention, your email will go unopened, no matter how great the content inside is. Here are 10 tips to help you write subject lines that convert.

1. Keep it Short

Mobile devices cut off long subject lines. Aim for 40 characters or less to ensure your message is fully visible on all screens.

2. Create Curiosity

Make them wonder what's inside. Questions and teasers work well. For example: 'You won't believe this...' or 'Are you making this mistake?'

3. Use Emojis (Wisely)

Emojis can increase open rates by adding visual interest and conveying emotion. However, don't overdo it. One or two relevant emojis are usually enough.

4. Personalize It

Using the recipient's name in the subject line can boost open rates by 26%. But go beyond the name—reference their location, past purchases, or interests.

5. Use Power Words

Words like 'Urgent', 'Exclusive', 'Free', and 'Limited Time' trigger a psychological response and encourage action.

6. Avoid Spam Triggers

Stay away from all caps, excessive exclamation points, and words like 'Cash', 'Guarantee', or 'Risk-Free'. These can trigger spam filters.

7. Create Urgency

Give them a reason to open now. Deadlines and scarcity are powerful motivators. Example: 'Last chance to save 50%'.

8. Be Honest

Don't use clickbait. Your subject line should accurately reflect the content of the email. Misleading subject lines damage trust and increase unsubscribe rates.

9. A/B Test

Never guess. Test different subject lines to see what resonates with your audience. Most email platforms make this easy to do.

10. Use Preheader Text

The preheader is the snippet of text that appears next to or below the subject line. Use it to expand on your subject line and provide more context.

MailBolt
Written by
MailBolt™ Team