ChatGPT for email marketing: when to use it, when to skip it

ChatGPT for email marketing: the myth and the reality

That’s the pitch that got sold all through 2024. The promise: “give your product to ChatGPT, it writes the campaign, you send it.”

It produces emails you feel are AI-generated:

• Repetitive structures (“Dear customer,…” / “Discover our…”)
• Hollow adjectives (“exceptional”, “incredible”, “innovative”)
• Generic CTAs (“Order now”)
• No tension, no point of view

And your recipients feel it. Open rate steady, click rate dropping, unsubscribes climbing.

ChatGPT doesn’t replace a copywriter. But used well, it speeds up 60% of your production.

The 8 use cases that actually work

1. Brainstorm 20 subject line angles from a brief

Prompt that works:

“I’m launching an email campaign on [product X] for a [persona] audience. The key message is [insight]. Give me 20 short subject lines (40 characters max), varying structures (question, number, intrigue, urgency, social proof, direct benefit). Skip hollow superlatives.”

Result: you get 5–8 usable subjects (out of 20). Much faster than writing them by hand.

2. Rewrite an existing email in a different tone

Prompt that works:

“Here’s the current email: [paste content]. Rewrite it keeping the same structure and message, but with a [more direct / warmer / more expert] tone. Keep the same length. Keep the same CTA.”

Result: great for A/B testing tones without starting from scratch.

3. Generate preview text variations for a campaign

Prompt that works:

“Here’s my email subject line: [subject]. Here are the first 3 lines of content: [paste]. Give me 10 preview texts (60 characters max) that complement the subject without repeating it, that intrigue or reassure.”

Result: an underused lever on click rate.

4. Break down a vague brief into an actionable one

Prompt that works:

“My manager gave me this brief: ‘[original brief]’. Ask me the 10 questions to clarify before I can produce the campaign (audience, KPI objective, tone, content, CTA, deadline, constraints, success metrics).”

Result: you walk away with a brief 5x more precise, without having to write it yourself.

5. Audit an email before sending

Prompt that works:

“Here’s an email I’m about to send: [paste]. Play the role of a skeptical recipient receiving it. What are the 5 frictions or objections that could keep them from clicking? Be critical, not complacent.”

Result: you spot 2–3 fixes doable in 5 minutes that can shift click rate by 0.5 to 1 point.

6. Translate an email while keeping the tone

Prompt that works:

“Here’s a French email: [paste]. Translate it into English for a [UK / US] audience. Keep the tone, the wordplay if possible, and adapt cultural references. Don’t translate word for word.”

Result: far more usable than Google Translate.

7. Generate micro-copy (buttons, alts, headers)

Prompt that works:

“My current CTA is ‘Buy now’. Give me 15 alternatives that:

• Use a different action verb
• Avoid ‘click’ and ‘now’
• Add an implicit benefit or promise
• Stay under 25 characters”

Result: immediate click rate boost on A/B tests.

8. Summarize 50 customer reviews to find copy angles

Prompt that works:

“Here are 50 customer reviews on [product]: [paste]. Identify:

• The 5 benefits customers mention most often (with quotes)
• The 3 most frequent objections / disappointments
• The specific vocabulary customers use (to reuse in emails)”

Result: your copy gets 3x sharper because it speaks your customers’ language.

The 4 cases where you’re wasting your time

1. Generating a full email (subject + copy + CTA) in one prompt

You get an email that looks fine on the surface, mediocre on performance. Go modular instead: briefing + structure + copy block by block.

2. Asking ChatGPT to analyze your KPIs without context

Pasting a KPI table into ChatGPT and asking “what’s wrong” produces generic answers. ChatGPT hasn’t seen your emails, your flows, your audience. It can only paraphrase best practices.

For a real diagnosis, you need a tool that sees your actual data, not a blindfolded LLM.

3. Letting ChatGPT write your brand voice

ChatGPT doesn’t know your brand. If you ask it “write in [my brand]‘s tone,” it’ll extrapolate from what it knows about the market and produce a generic vertical voice.

For it to write in your tone, you need to give it:

• 10 high-performing historical emails as reference
• A precise description of the tone (3–5 attributes with examples)
• Explicit “never do this” rules (banned words, banned structures)

4. Asking it for “Klaviyo best practices”

ChatGPT’s Klaviyo knowledge is pre-2024. For up-to-date best practices, it’s missing recent context (MPP, deliverability changes, benchmark shifts).

Stick with specialized, up-to-date sources.

The right ChatGPT + email production workflow

Here’s the workflow we recommend, combining human + AI properly.

Step 1, Brief (human). You define the audience, objective, key message, CTA. 10 minutes.

Step 2, AI brainstorm (5 minutes). ChatGPT generates 20 subject angles, 10 opening hooks, 15 CTAs.

Step 3, Selection (human). You pick the 3 best angles and the 2 best CTAs. 5 minutes.

Step 4, AI draft (5 minutes). ChatGPT writes the email draft from the chosen angle.

Step 5, Edit (human). You cut the fluff, add the twist, validate the tone. 15 minutes.

Step 6, AI audit (5 minutes). You ask ChatGPT to audit the email from a skeptical angle. You fix the frictions.

Step 7, A/B (human). You test subject and CTA. You measure.

Total time: 45 minutes instead of 2 hours pure human. And equal or better performance.

The important reminder

ChatGPT is a tool. Like all tools:

• Used well, it saves you 60% of the time
• Used poorly, it costs you revenue without you noticing

Don’t ship it without measurement. Systematically compare KPIs for “AI-assisted” vs “pure human” emails over 4–6 weeks before standardizing a workflow.

What Retain does differently

Retain is not a ChatGPT wrapper. It’s a copilot that:

• Sees your Klaviyo data (templates, flows, KPIs, audience)
• Analyzes continuously, not prompt by prompt
• Learns your brand voice (by reading your historical emails)
• Gives you actionable recommendations with impact in €

Keep ChatGPT for copy production. Retain for analysis, detection, and prioritization.