ChatGPT Prompts for Email Subject Lines: 12 Options

ChatGPT prompts for email subject lines help you draft clear, proof-based subjects and preheaders from your offer and audience notes. Paste only proof you can defend. These prompts do not invent open rates, fake scarcity, or testimonials. Test finalists in your ESP.

CAN-SPAM bans deceptive subject lines: no fake "RE:" or "FWD:" and no clickbait that misstates what is inside.

Brief the email before the subject

1. Offer and goal one-liner

Offer: [offer]. Email goal: [click/reply/renew/attend]. Audience: [segment]. Write a one-line brief ChatGPT should optimize subjects for. No metrics inventing.

2. Proof allow-list

Proof I may cite: [list with sources]. Rewrite any draft subject that uses a number not on this list.

3. Tone and spam avoid list

Tone words to prefer/avoid: [list]. Spam-avoid words: [list]. Constraints: [character caps, no ALL CAPS, compliance]. Restate as rules for subject drafts.

Generate angles, not clickbait

4. Ten subjects by angle

Using [brief], write 10 subjects grouped by clarity, proof, curiosity without clickbait, question, and utility. Respect [constraints] and [spam avoid].

5. Preheader pairs

For each subject in [list], write a preheader that does not repeat the subject verbatim and stays honest to [offer].

6. Curiosity without bait

Rewrite these bait-y subjects to keep curiosity but remove fake mystery or missing nouns: [subjects].

Choose and test

7. Rank for the goal

Rank my subjects for [EmailGoal] with a one-line why each, using only [Offer], [Audience], and [ProofAllowed]. No predicted open rates.

8. A/B pair builder

From [subjects], propose 2 A/B pairs that change one variable each (proof vs clarity, question vs statement).

9. Mobile truncation check

Rewrite [subjects] so the first ~35 characters still make sense on mobile. Keep meaning; do not add hype.

Compliance and handoff

10. Spam-risk flagger

Flag any line in [subjects] that hits [SpamAvoid] or over-claims vs [ProofAllowed]. Suggest a safer rewrite.

11. Sequence subject ladder

Email sequence goals: [email 1/2/3 goals]. Write subjects that do not repeat the same hook across steps, using [Offer] only.

12. ESP paste card

Format my top subject, preheader, and UTM notes (only if I provide UTMs: [utms or none]) as a paste card for my ESP.

Run the full subject kit with one prompt

The flagship Email Subject Line Options From Offer Audience Proof builds ten angled subjects, preheaders, top-3 ranking, A/B pairs, and spam flags in one pass. Its example promotes a 14-day read-only warehouse pilot with Harborline proof only.

Related prompts

Full sequences: sales email sequence and sales email prompts. Lifecycle flows: Klaviyo flow outline. Internal announcements: corporate communications kit. Campaign framing: marketing campaign launch plan and campaign prompts.

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