How Is an Email Subject Line Written to Earn More OpensUpdated 5 days ago

The subject line is the single most important piece of copy in any email campaign. It determines whether the email gets opened — and an email that does not get opened cannot generate a sale, a click or any other outcome regardless of how good the content inside is.

I treat subject line writing as a distinct craft within the broader email writing process.

What I apply when writing every subject line:

Specificity over cleverness. "Your cart is waiting" earns fewer opens than "The product you saved sells out most Thursdays." The specific detail creates urgency based on reality rather than manufactured pressure.

Curiosity without confusion:

• A subject line that opens a loop — creates a question the reader's mind wants answered — reliably earns more opens than a descriptive subject that gives away the full content
• But the subject must be clear enough that the reader knows roughly what they are opening — confusion generates distrust faster than curiosity generates interest

Length and format. Most email clients show 40 to 60 characters of subject line on mobile. The key hook needs to land within that visible window — characters that get cut off are entirely wasted.

Every subject line I write is paired immediately with preview text designed to complement it — giving the reader a second reason to open before they have made the decision to click.