Question 1

How is the subject line score calculated?

Accepted Answer

The tester checks length (ideal 30–50 characters), spam trigger words, ALL CAPS words, exclamation marks, deceptive Re:/Fwd: prefixes, emoji, and whether you've personalized it with a variable like {{first_name}}. Each issue deducts points and comes with a specific fix.

Question 2

Should I use emoji in cold email subject lines?

Accepted Answer

Avoid them for B2B cold email. Emoji can trigger spam filters and look unprofessional to many buyers. Plain, specific text consistently outperforms decorated subjects in cold outreach.

Question 3

Does personalization really improve open rates?

Accepted Answer

Yes. Including the recipient's name or company signals the email was written for them, not blasted. It's one of the few subject-line tactics with consistently proven lift — the tester rewards it in your score.

Subject line tester

What makes a good cold email subject line?

Questions, answered

Stop guessing. Start booking meetings.