Which tool to choose
No neutral lists. Choose based on how you work.
You write the copy and then paste it into your email platform (Mailchimp, Brevo, etc.): use a general-purpose model. ChatGPT and Claude are the most flexible email copywriting tools: give them context on product, audience and goals and they generate drafts, subject lines, sequences and entire campaigns.
- Claude if the priority is copy that sounds human. It tends to produce the most natural drafts; where other models fall back on cautious corporate language, it adapts tone better. It is the first choice for anyone who cares about brand voice.
- ChatGPT if you want a single do-it-all assistant and the widest ecosystem of extensions. The free version handles any format, from emails to social posts, with clean, readable copy.
- Gemini if you live inside Google Workspace and need real-time search. It integrates with Docs and Gmail and pulls from up-to-date information, useful when you cite recent news or data. The paid plan is the most cost-effective for heavy use.
You want the copy to be created right inside the sending platform: GetResponse or Brevo. They generate subject lines, headings and body from a single prompt, with tone and length options, and from the same campaign you get the linked landing page without switching tools. It is the right choice if you want to avoid copy-pasting between different applications.
To start at zero cost, free ChatGPT is the most solid entry point. If instead your bottleneck is managing contacts and sends, an integrated tool pays off right from the start.
How to do it
From the browser or the app of the model you choose, the path doesn't change.
- Open a new conversation in your tool (ChatGPT, Claude or Gemini).
- Paste the complete prompt below, replacing only the data between quotes. Don't leave fields empty.
- Read the draft. If the subject line doesn't convince you, ask: "Give me 5 more subject line variants, under 50 characters".
- Check: make sure there is a single clear call to action and that every number or promise in the copy is real. If the AI wrote "90% of customers", delete it unless you actually have that data.
- Paste the copy into your sending platform and send a test to your own inbox.
The working syntax for a promotional email:
Act as an email marketing copywriter. Write a promotional email.
Product/service: online photography course for beginners, 8 weeks
Audience: adults 30-50 who own a DSLR but shoot only in auto mode
Goal: sign up by Friday, 20% discount for the first 30
Tone: encouraging, like an expert friend, no technical jargon
Constraints: 150 words max, a single call to action, give me 3 subject line variants under 50 characters
Don't make up statistics or testimonials. If you need data I didn't give you, leave it as a placeholder to complete and flag it to me.
For a content newsletter (not direct selling):
Write a weekly newsletter for my list.
This week's topic: three mistakes that kill houseplants in winter
Audience: people with a brown thumb who want easy plants
Tone: light, ironic, practical
Structure: subject line + opening that hooks in 2 lines + the three points + closing with a question that invites a reply
Length: 250-300 words
Use only everyday language. No brochure tone. Don't insert data or research I didn't provide.
The anti-fabrication instruction inside the prompt is the part that saves you. The most costly mistake is publishing the first draft without checking it: always verify the output, because AI can make up information.
Concrete example
Marco runs a small coffee roastery and needs to announce a new Ethiopian single-origin coffee. He opens free ChatGPT and adapts the first prompt: product "single-origin Ethiopia Yirgacheffe coffee, floral and citrus notes", audience "already-subscribed customers who have bought at least once", goal "try the new batch with free shipping over €25", tone "passionate but concrete".
ChatGPT returns three subject lines. Marco discards "Discover our new coffee" because it's generic and chooses "Ethiopia in a cup: the floral batch has arrived". The body was good but contained the phrase "loved by thousands of customers": he deletes it, because the batch is brand new and it isn't true. He adds a line of his own about the producer he visited. He pastes it into Brevo, sends a test to himself, checks that the shop link works and that the unsubscribe link is there, then schedules the send. Email ready in about 15 minutes instead of an hour, with his voice and zero made-up data.
When it does NOT work (and how to fix it)
If the AI makes up numbers or testimonials
This is the most frequent risk. Fix: put the instruction "Don't make up statistics or testimonials" in the prompt (it's already in the prompts above) and, while rereading, delete every figure you can't back up with your own data.
If the copy sounds robotic or "brochure-like"
This happens especially with bare prompts. Fix: paste 3-5 points into the prompt that describe your brand voice. The models stick to them well, and it's the biggest quality improvement you get without changing tools. Alternatively, paste an old email of yours that you liked and ask "write in the same style".
If the email "breaks" in the mail client
When you ask the AI to generate the email's graphic HTML code, expect problems: the models struggle to produce HTML compatible with all mail clients and tend to leave out mandatory elements, like the unsubscribe link. Fix: don't have the AI generate the graphic code. Have it give you the text and build the layout inside your email platform's editor, which handles compatibility and unsubscribe for you.
If the free output seems poor to you
On some dedicated tools, quality goes up when you pay. Before subscribing, try improving the prompt (context + tone + an example of your voice) on the free plan of ChatGPT or Claude: they handle email copywriting without trouble even in the free version. Switch to paid only if you need voice memory, team collaboration or saved templates.
A tip from someone who actually uses it
Don't ask the AI "write me the newsletter" and be done. First ask it for five subject lines, choose one, then have it write the body around that subject line. The subject line decides whether the email gets opened, and writing it last is the reason so many AI-generated emails go unread. Also keep a note with 5 points on your brand voice to paste every time: it's the difference between copy that seems yours and copy that seems anyone's.
Frequently asked questions
Which AI do I choose if I only use one?
ChatGPT, for balance and reach. It handles email drafting, summaries, translation and quick research without marked weaknesses. But if your absolute priority is copy that doesn't seem machine-written, start with Claude.
Can I use it for free or do I have to pay?
You can do a lot for free. The free version of ChatGPT handles any format; the limits are the absence of brand voice memory, team collaboration, saved templates and integration into workflows. If you want ready-made templates without spending, the free plan of Rytr offers 10,000 characters per month with templates and tone selection, even though the quality is below ChatGPT.
Does the AI also write the subject line and decide when to send?
Yes, and integrated platforms do it better than a model alone. Besides suggesting subject lines, GetResponse and Brevo include send-time optimization and list segmentation, which work together with the copywriting. A general-purpose model only gives you the text: you decide the timing.
If everyone uses AI now, won't my emails be the same as everyone else's?
It's the serious objection, and it's partly true. At this level of adoption, using ChatGPT with a prompt is the starting baseline, not an advantage. The difference isn't made by the tool but by what you put into it: your stories, your brand voice and the real data only you have. AI takes you from the blank page to the draft; what makes it yours you add yourself.