Writing Email Subject Lines People Open

The subject line decides whether an email is opened, ignored or deleted. A few principles make a big difference.

Be clear before clever

Readers scan their inbox quickly. A subject line that clearly says what is inside often beats a clever one that needs decoding.

Lead with the benefit

Tell the reader what they get: a tip, a solution, an invitation, a saving. Focus on them, not on the sender.

Keep it short

Long subject lines are cut off on mobile. Put the most important words first.

Use curiosity carefully

A little intrigue works, but the email must deliver on the promise. Misleading subject lines damage trust and increase unsubscribes.

Personalise where it helps

Personalisation based on interests, location or recent behaviour is more effective than a first name alone.

Write the preview text too

Preview text appears next to or below the subject line. Use it to add context or a second hook instead of letting it default to "View in browser".

Avoid spam triggers

Excessive capitals, multiple exclamation marks and aggressive sales language can hurt deliverability and look untrustworthy.

Subject line formulas to test

• A question the reader is asking.
• A specific number of tips or steps.
• A clear deadline for a genuine offer.
• A short, personal-sounding line from a named sender.

Test systematically

A/B test one element at a time and use the results to build a picture of what works for each audience.

Let our writers help

oceanone's email marketing team writes subject lines, preview text and email copy that convert.