How to use ChatGPT to write your next email campaign, step by step

THIS WEEK: This week we show you exactly how, with a real input, a real output, and the real editing process that turns an AI draft into something worth sending.

Writing an email campaign from a blank page is one of the more tedious tasks in small business marketing. You know roughly what you want to say. You know who it is for. Getting from that vague sense to actual finished copy, with a subject line, a body, and a call to action that does not sound like everyone else's marketing email, takes longer than it should.

ChatGPT genuinely helps with this, but not in the way most guides describe it. The common advice is "ask ChatGPT to write an email campaign" as if that alone produces something usable. It does not. What it produces is a competent, generic first draft that needs a specific editing process to become something worth sending to actual customers. This issue walks through that process using a real example, from the initial brief through to a finished piece of copy, so you can see exactly what changes and why.

One thing worth knowing before you start: ChatGPT's underlying model changes fairly often. As of mid-2026, ChatGPT runs on the GPT-5.6 family, with free and lower-tier users getting a version called Luna and paying Plus and Pro users getting a stronger version called Sol. You do not need to understand the technical differences. What matters practically is that ChatGPT has become noticeably better at following detailed instructions and staying on brief over the past year, which means the more specific and detailed your prompt, the better the output. Vague prompts produce vague copy. Detailed prompts produce something much closer to usable.

The Walkthrough: A Real Email Campaign, Start to Finish

Let us say you run a small landscaping business and you want to send an email to your existing customer list promoting your fixed-price autumn garden tidy-up service ahead of the season. Here is the actual process.

Step one: the input. This is the part most people get wrong. They type something like "write me a marketing email about our autumn garden service." That is not enough information for ChatGPT to produce anything specific to your business. Here is what an actual usable prompt looks like:

"I run a landscaping business called [business name] in [location]. I want to write an email to my existing customer list promoting a fixed-price autumn garden tidy-up service. The service includes hedge trimming, leaf clearance, and bed maintenance, and costs £120 for an average garden. It needs to be booked before the end of October because we get fully booked in November. The tone should be friendly and direct, not salesy. My customers are mostly homeowners aged 40 to 70 who value reliability over flashiness. Write a subject line and an email body, around 150 words, with a clear call to action to book."

Notice what is in that prompt: who you are, what you are selling, the specific price, the specific deadline, the tone, the audience, and the length. Every one of those details changes what ChatGPT produces. Without them you get generic marketing copy. With them you get something that at least starts from your actual situation.

Step two: the output. Here is roughly what ChatGPT produces from a prompt like the one above.

Subject line: "Your garden, sorted before winter (£120, book by 31 October)"

Body: "Hi [Name], autumn has a habit of sneaking up on gardens. Fallen leaves pile up, hedges get shaggy, and beds start looking neglected before you know it. Our autumn tidy-up sorts all of it: hedge trimming, leaf clearance, and bed maintenance, for a fixed £120. We are already filling up our November slots, so if you want your garden sorted before winter properly sets in, the best time to book is now. Reply to this email or call us on [number] to get a date in the diary. Thanks, [Name]."

That is a genuinely solid first draft. It is on brief, the right length, and it has a clear structure. It is also not ready to send.

Step three: the edit. This is the part that matters most and the part most people skip. Here is what needs to change and why.

The subject line is functional but generic. Subject lines between 61 and 70 characters have the highest average open rate at 32.1%, and this one is well under that at 47 characters, which is actually fine for mobile readability, but it does not create any specific curiosity or urgency beyond the date. A stronger version references something more specific to your actual customers: "Still got leaves everywhere? Let's sort that before November." This is more conversational, references a real, relatable annoyance rather than a generic pitch, and still fits comfortably within mobile preview limits, which cut off after roughly 30 characters, so the most important part needs to be at the front regardless of which version you use.

The body is competent but generic in the way all first drafts from AI tend to be. "Autumn has a habit of sneaking up on gardens" is a perfectly fine sentence and also a sentence that could have been written about any landscaping business anywhere. It has no specific detail that only you would know. This is where you add what the AI cannot: a specific observation from your actual work. Something like "we have already had three calls this week from people who left it too late last year and ended up on our January waiting list" is a real, specific detail that no AI would invent because it is about your actual business history, and it does more to create urgency than any generic line about autumn sneaking up.

Replace "Reply to this email or call us on [number]" with something more specific about what happens next. "Reply with your postcode and we will send you the next available date" is a clearer, lower-friction call to action than a generic invitation to call, because it tells the reader exactly what to do and what they get in return.

Cut anything that sounds like it was written by an AI trying to sound friendly. Phrases like "properly sets in" and the slightly performed casualness of "has a habit of sneaking up" are the kind of thing that reads fine on first pass and slightly off on a second read. Replace them with how you would actually say it to a customer standing in their garden.

ChatGPT (chatgpt.com) is the tool used throughout this walkthrough. Free plan available, which as of mid-2026 defaults to the GPT-5.6 Luna model with unlimited text chats for free users. The Plus plan, around £17 a month, gives you the stronger Sol model along with more usage headroom for longer sessions and file uploads. For writing a single email campaign, the free tier is entirely sufficient. Where the paid plan becomes worth it is if you are running this process regularly across multiple campaigns and want faster, more consistently on-brief output without hitting usage limits. Link: https://chatgpt.com

Pick the next email you need to send. Write a prompt that includes: what your business does, what you are promoting, the specific price or offer, the deadline if there is one, the tone you want, who your audience is, and the length you need. The more specific you are, the less editing you will need to do afterwards.

Read the output. Do not send it as-is. Go through it and ask: does any sentence here sound like it could apply to any business, not just mine? If yes, replace it with a specific detail from your actual experience. Is the call to action as clear and low-friction as it could be? If not, make it more specific about exactly what happens when someone responds.

Read the whole thing out loud. If it does not sound like something you would actually say to a customer, change the words until it does. That last step alone catches most of what makes AI-written copy feel slightly off.

NEED HELP? In over your head? Wearing too many hats already? No idea where to start? I can help you. Alternatively, feel free to WhatsApp me on 07800596333!

Grammarly (grammarly.com) is worth using as a final pass after your ChatGPT draft is edited. It catches tone inconsistencies and readability issues that are easy to miss after you have been staring at the same paragraph for twenty minutes. The free plan covers basic grammar and tone checking.

Your own sent folder is worth mining before you write your next prompt. Look back at emails you have written yourself in the past, ones that got good responses, and paste a couple of them into ChatGPT with the instruction "match this tone and style" before asking for the new campaign. This gives ChatGPT a genuine reference point for how you actually write, which produces a first draft that needs considerably less editing to sound like you.

In 2026, inboxes are more crowded with AI-generated content than at any point before, and both spam filters and readers have become noticeably better at detecting the specific flatness of unedited AI copy. Subject lines and body copy that feel generic, over-polished, or slightly too eager are increasingly filtered out or ignored, not because AI is banned but because AI-flavoured writing has become instantly recognisable and readers have started to tune it out the way they tune out an obvious advert.

The businesses getting genuine value from ChatGPT for email campaigns are not the ones sending the first draft. They are the ones using it to solve the blank page problem and then doing the actual work of making it sound like a real person who knows their actual customers wrote it. That editing process, adding the specific detail, cutting the generic phrasing, and reading it aloud to check it sounds like you, is where the real value gets created. ChatGPT gets you moving. The finished, sendable email is still something you make.

Need someone to do this properly rather than doing it yourself? I have been doing this for 17 years. Get in touch. Alternatively, feel free to WhatsApp me on 07800596333!