Strategy
Part of Email copywriting for people who want the details
Email copywriting checklist: subject, preheader and opening
An email copywriting checklist for the first lines a recipient sees: From name, subject, preheader and opening, with failure cases and a review record.
What to take away
- Review the From name, subject, preheader and opening together, because the recipient meets them as one unit.
- The subject must describe the message that follows, so fake replies, invented account issues and misleading urgency are fails.
- Do not rely on a universal character count. Make the core topic clear before truncation in the inboxes you actually target.
- Mark each item pass, fail, unknown or not applicable with evidence, owner, correction and review date.
What the recipient sees first
The four lines a recipient meets first need to agree with each other and with the message that follows. Review them as a set, in the inbox, before anyone polishes the body copy.
| Line | It must | It fails when |
|---|---|---|
| From name and address | Identify the sender | The sender is unclear or the reply route is not monitored |
| Subject | Explain the topic accurately | It fakes a reply, invents an account issue or exaggerates urgency or savings |
| Preheader | Add information the subject lacks | It repeats the subject or contradicts it |
| Opening | Give the reason for contact | It starts with company praise before relevance |
Settle the brief before the first line
A subject line can only be accurate if the writer knows what the message is for. Define the audience or segment, situation, message type, sender, market, timing, desired action, the outcome if the recipient takes no action, owner and constraints.
Brief and Context Checklist
- Audience, situation, message type, sender, market, timing
- Decision, non-action, owner, constraints, guardrails, outcome
- Product facts, customer research, offer terms, objections
- Required language, destinations, journey context, prior learning
- Named writer and business approvers assigned
Verify product facts, offer terms and destinations against current sources, and name the writer and the approvers. Wider voice and structure advice sits in email copywriting, and the offer terms belong to the campaign planning checklist.
From name and reply route
Confirm that the From name and address identify the sender and that the reply route is monitored. A recipient who answers a message and hears nothing learns that the sender cannot be trusted.
- The From name is one the recipient would recognize.
- The sending address matches the sender named in the message.
- Someone reads replies, and the owner is named in the record.
- The sender line, subject and opening all describe the same relationship.
Subject line: accuracy before cleverness
Check that the subject avoids fake replies, invented account issues, misleading urgency, unsupported savings and content mismatch. A subject earns the open by describing the message, not by borrowing the look of a different kind of mail.
The FTC's CAN-SPAM guide says don't use deceptive subject lines and that the subject line must accurately reflect the content of the message. Treat that as a floor for every commercial message, and review the subject against the body, not against the campaign name.
Savings and urgency need the same discipline. The FTC says that claims in advertisements must be truthful, cannot be deceptive or unfair, and must be evidence-based, so a subject that promises savings needs the evidence ready when the reviewer asks for it.
Preheader: add, do not repeat
The preheader should add information the subject does not carry, such as the reason for contact or the key condition. Read the two together, because the inbox shows them side by side.
If the preheader repeats the subject, the space is wasted. If it contradicts the subject, the message has a mismatch before the recipient opens it. Either result is a fail on the review record.
Opening: relevance before company praise
Make the opening relevant to the recipient before any company praise. The first lines should confirm why the message arrived and what it concerns, in plain words that a reader with no context can follow.
A welcome email can explain the signup, while a renewal or win-back opening can name the terms in play. Journey context matters, so check the opening against the subscriber journey stage and, for lapsed subscribers, against the re-engagement examples.
Render it where people will read it
Render the message in the intended inboxes. Do not rely on a universal subject or preheader character count, because display varies by client and device, and make the core topic clear before truncation.
Use a tool such as Litmus or GlockApps to check inbox rendering and subject and preheader truncation. Treat spam-word matches and scores as diagnostics, not a guaranteed pass or fail. The email design guidance covers how the same message holds up on small screens and with blocked images.
Record the review
Store the decision record in the campaign document or the ticket that carries the final send approval. One row per failed item is enough, with evidence, owner, correction and review date.
| Item | Status | Evidence | Owner | Correction |
|---|---|---|---|---|
| Subject matches content | Fail | Subject suggests an account alert, but the body is a promotion | Copy owner | Rewrite the subject to name the promotion |
Repeat the review on the final rendered message after any change to copy, data, offer, template or destination. The campaign planning best practices show where this review sits before the staged release.
Common questions
Who owns the review?
One copy owner coordinates product, evidence, legal, brand, accessibility, data, delivery, service and destination owners without replacing their decisions.
Is there a correct subject line length?
No universal count applies. Check the real rendering in the inboxes you target, and put the core topic where truncation will not remove it.
Should every line receive equal review?
No. Review consequence first: identity, material claims, price, conditions, deadlines, disclosure and customer choice deserve deeper evidence than phrasing preferences.
