Disclosure: some links are affiliate links. I may earn a commission at no extra cost to you.
If you’ve typed “write me a marketing email about my sale” into ChatGPT and gotten back something that starts with “In today’s fast-paced digital landscape…” — you’re not doing anything wrong. That’s just what happens with a vague prompt. This guide covers how to write marketing emails with AI so they actually sound like you, including the exact prompt structure we use, a side-by-side test of three tools on the same brief, and a compliance checklist most AI guides skip entirely.
Why AI-Written Emails Usually Sound Fake (and How to Avoid It)
There are a handful of words that show up so often in AI drafts they’ve become a running joke in marketing circles: unlock, elevate, game-changer, dive in, in today’s digital landscape, seamless, supercharge. None of these are wrong exactly — they’re just generic. They’re the words a model picks when it has no specific information to work with.
That’s really the root issue: generic prompts produce generic emails. If you ask for “a marketing email about my spring sale,” the AI has nothing to anchor on except marketing-email clichés it’s seen a million times. If you tell it your actual discount, your actual customer’s biggest complaint, and three words that describe how you talk, it has something real to build from.
“Brand voice” sounds abstract, but in practice it’s just three things: the words you use (and don’t), your typical sentence length, and whether you write like a friend or like a press release. Once you define those on paper, AI tools follow them surprisingly well.
Build a One-Page Brand Voice Sheet Before You Prompt Anything
This takes about 10 minutes to fill out once, and you’ll reuse it for every email after. Create a simple doc with these fields:
- Tone words: 3-5 adjectives (e.g., “direct, warm, a little blunt, no corporate speak”)
- Banned words/phrases: your personal list — start with unlock, elevate, game-changer, in today’s world, seamless
- A sample of your past writing: paste in one real email or social post you wrote yourself
- Audience pain points: 2-3 specific problems your customers actually mention
- Offer details: price, deadline, what’s included, what makes it different
Paste this sheet at the top of every AI conversation before you ask for a draft. It’s the single biggest lever for making output sound less robotic, and it saves far more editing time later than it costs to set up.
The 4-Part Prompt Framework for Marketing Emails
Once your voice sheet exists, structure every email prompt the same way:
- Context: who the audience is, what the offer is, why now
- Structure: ask for a subject line, a one-line hook, 2-3 short body paragraphs, and a single clear CTA
- Voice constraints: paste your tone words and banned phrases; specify reading level (aim for 6th-8th grade) and a word count (150-250 for most promo emails)
- Output format: ask for plain text, no markdown or bullet symbols, and 3 subject line options instead of one
Here’s a copy-paste template:
“You’re helping me write a marketing email. Context: [who the audience is, what the offer is, deadline]. Structure: subject line, a one-sentence hook, 2-3 short paragraphs, one CTA button line. Voice: write like this sample — [paste past email]. Use these tone words: [list]. Never use these words: unlock, elevate, game-changer, seamless, in today’s world. Reading level: 7th grade. Length: under 200 words. Output as plain text with 3 subject line options at the top.”
Side-by-Side Test: ChatGPT vs Claude vs an Email-Specific AI Tool
We ran the identical brief above through ChatGPT (GPT-4), Claude, and Copy.ai, using the same voice sheet, for a real product-launch email announcing a $20-off early-bird price on a course.
ChatGPT’s first draft followed the structure well but still slipped in “elevate your skills” once, even with the banned list. It needed about 3 small edits.
Claude’s first draft stuck closest to the sample voice and avoided banned words completely, but ran slightly long and needed trimming by about 40 words.
Copy.ai’s draft, using its email template rather than a free-form prompt, produced the most “template-shaped” result — clear structure, but it leaned more generic and needed the most rewriting to sound personal, even though it followed formatting instructions perfectly.
Overall, Claude needed the least editing in this test, ChatGPT was a close second and most flexible for iterating, and Copy.ai was fastest if you just want a structural starting point and don’t mind doing more voice editing yourself.
Cost at time of testing: ChatGPT Plus is $20/month (free tier available with lower limits), Claude Pro is $20/month (free tier available), Copy.ai starts around $36/month for its paid plans with a limited free trial.
Editing Pass: Turning an AI Draft Into Something You’d Actually Send
No AI draft should go out unedited. A quick pass makes the biggest difference:
- Add one specific detail by hand — a real number (“147 people signed up last round”), a customer’s first name, or a small anecdote. AI can’t invent true specifics, and specifics are what make an email feel human.
- Cut filler sentences. Look for any sentence that could apply to literally any business (“We’re excited to bring you this amazing opportunity”) and delete it.
- Read it out loud. If you stumble on a phrase or it doesn’t sound like something you’d say to a friend, rewrite that line yourself.
- Shorten the subject line. AI tends to write subject lines that are too descriptive; aim for under 50 characters and punchier phrasing.
Compliance and Deliverability Basics AI Won’t Handle For You
AI tools don’t know email law, and they will sometimes write subject lines that cross the line into misleading (“Your account will be closed” when nothing is actually being closed). Before sending anything, check:
- Unsubscribe link is visible and working — required by CAN-SPAM, no exceptions
- Your business’s physical address appears somewhere in the email footer
- Subject line is honest — it should describe what’s actually inside, not create false urgency that doesn’t exist
- No deceptive “from” name — it should clearly be your business, not a personal name pretending to be a stranger
- Spam-trigger words are minimized — terms like “free money,” “act now,” or excessive exclamation points can hurt deliverability even if they’re not illegal
Most email platforms (Mailchimp, ConvertKit, etc.) add the unsubscribe link and address automatically, but it’s worth confirming before every send, especially if you’re pasting AI-written HTML into a new template.
A Simple Weekly Workflow for Using AI to Write Emails
Once the voice sheet and prompt template exist, the most efficient approach is batching. Set aside one hour every few weeks and write 4 emails at once, using the same prompt framework with different offers plugged in. AI saves the most time on the first-draft structure and subject line options; you still write the personal details and do the final read-aloud edit yourself — that part doesn’t get faster, but it also only takes a few minutes per email.
Realistic time estimate: before AI, a single promotional email often took 45-60 minutes from blank page to send-ready. With a voice sheet and prompt template in place, that drops to roughly 15-20 minutes including editing. The setup takes about 30 minutes the first time, then pays off on every email afterward.
FAQ
Can AI write a full marketing email from scratch?
Yes, but a first draft from a vague prompt usually needs editing. Give the AI specific details (your offer, tone, audience, and a sample of past writing) and it gets much closer to a usable draft, though you should still edit it before sending.
Which AI tool is best for writing marketing emails?
There’s no single winner. ChatGPT and Claude are flexible and cheap (often free or around $20/month) but need good prompts. Email-specific tools like Copy.ai or Jasper come with built-in templates and can be faster if you’re not comfortable writing prompts, but they usually cost more per month.
How do I stop AI emails from sounding robotic or salesy?
Ban specific words in your prompt (like “unlock,” “elevate,” “game-changer”), feed the AI a real example of your past writing, and always add one specific detail by hand after the draft comes back, like a real number, a customer’s name, or a small story.
Is it legal to send marketing emails written by AI?
Yes, the law doesn’t care who or what wrote the email. What matters is that the email follows CAN-SPAM rules: no misleading subject lines, a visible unsubscribe link, and your business’s physical address included.
How much time does AI actually save on email marketing?
In testing, drafting a single promotional email went from roughly 45-60 minutes by hand to about 15-20 minutes including editing, once a brand voice sheet and prompt template were set up. The setup step takes time upfront but pays off on every email after that.
Do I need a paid AI tool to write good marketing emails?
No. Free versions of ChatGPT or Claude can produce solid drafts if you give them a detailed prompt and brand voice sheet. Paid tools add convenience and templates but aren’t required to get usable results.
That’s the full workflow: a voice sheet, a 4-part prompt, a quick edit pass, and a compliance check before you hit send. Browse more tested AI marketing workflows and honest tool comparisons on AI Marketing Now.