How to write marketing emails with AI, and what to check before you send

To write marketing emails with AI, give the model a short brief with your brand, audience, offer and limits, ask for a draft and a few variants, then check every fact, price, claim and the audience’s consent yourself. A connector such as Tellnod adds the real preview and a confirmation card, so a draft becomes a send only when you approve it.

From brief to approved send#

  1. Write a five-line brief

    State the goal, the audience, the offer with its exact terms, the one product or story to feature, and anything that must not appear. A brief this short takes two minutes and removes most rewrites.

  2. Ask for a draft and variants

    Ask for one full email plus three subject lines and two opening lines in different directions. Variants show you options you would not have written, and you keep the one that fits.

  3. Edit in plain words

    Reply with specific changes: “Cut the intro to one sentence”, “Use the fabric name, not ‘premium materials’”. Each pass should change one thing so you can see what improved.

  4. Check facts and claims

    Compare every price, date, discount code, product detail and claim against your store. The model writes what sounds plausible, not what is in your stock system.

  5. Preview and test

    Look at the email on a phone and on desktop, and send yourself a test. Read the subject, the preheader and the footer as a recipient would.

  6. Approve the send

    Confirm the audience is people who agreed to hear from you, then send or schedule. With a connector like Tellnod, this is the confirmation card that only you can press.

What AI does well in email marketing#

Language models are fast at the parts of email marketing that are mostly writing. For a small shop without a copywriter, that covers most of the hours a campaign takes. The model is weaker wherever the answer lives in your own data: stock levels, real prices, who opted in, and what your customers bought.

Where AI helps with a campaign, and what stays with you
TaskWhat AI does wellWhat you check
DraftingA complete email from a short brief, in secondsFacts, prices, dates and links
VariantsSeveral subject lines, openings and calls to action to compareWhich one is honest and fits your shop
ToneRewriting the same message warmer, shorter or more formalThat it still sounds like you
TranslationA fluent version for another marketSizes, currency, legal footer and idioms, ideally with a native reader
Segment ideasSuggesting audiences, such as repeat buyers or people who bought one categoryThat the data exists and those people consented
ResultsSummarizing numbers you paste in and suggesting a next testThat the comparison is fair, such as same audience size and send day

A sensible split: let the assistant produce options and do the rewriting, and keep the decisions (what to offer, to whom, and whether it goes out) with a person.

Where a person has to check#

Anthropic’s own guidance says Claude can produce text that is factually incorrect, and that critical information should always be validated S2. ChatGPT works the same way. In a marketing email, an invented detail is a promise to customers, so five things always get a human review.

  • Facts and prices. The model fills gaps with plausible details: a discount that sounds right, a delivery promise, a fabric weight. Paste the real numbers into the brief and check the draft against them.
  • Claims. In the US, the FTC expects advertising to be truthful and non-deceptive, with evidence for a claim in hand before the ad runs S3. “Warmest sweater we have made” needs a basis; “100% merino” needs to be true.
  • Subject lines. CAN-SPAM prohibits deceptive subject lines S4, and Google’s sender guidelines say the subject and display name should accurately represent the sender and content, with no “Re:” or “Fwd:” unless the message is a real reply or forward S5.
  • Consent. A model can suggest an audience; it cannot know who agreed to hear from you. Send only to contacts with a consent record. See email marketing consent laws.
  • Brand voice. Drafts drift toward a generic register. Read the email aloud; if it could be from any shop, it needs your details.

The FTC is clear that a business stays responsible for its marketing email even when another company sends it S4. The same logic applies to a draft from an AI: the sender owns the content.

Give the model your brand context#

Anthropic suggests treating Claude like a capable new employee who lacks context on your norms, and explaining the reason behind an instruction, because the model generalizes from the explanation S1. For email, that context is a brand brief you write once and paste at the start of each chat, or keep in the place your AI app stores standing instructions.

  • Who you are in one sentence, and who buys from you.
  • Three words for your voice, and three it should never sound like.
  • Words you use and words you avoid (for example “knit” instead of “garment”).
  • Your standing terms: shipping threshold, returns window, how you handle discounts.
  • Two past emails that worked, pasted in full as examples.

An example brief

“We are Ninefold, a small apparel brand selling knitwear, outerwear and basics online. Customers are mostly 28–45, buy a few good pieces a year, and care about fabric and fit. Voice: plain, warm, specific. Never: hype, exclamation marks, ‘must-have’, ‘elevate’. We say ‘knit’, not ‘garment’. Free shipping over $120, 30-day returns. We run two sales a year and do not invent urgency. Below are two emails our customers liked.”

Examples carry more weight than adjectives. Anthropic recommends a few relevant, varied examples as one of the most reliable ways to steer tone and structure S1; OpenAI’s prompting guide also advises giving examples and the context the model needs S6.

How to avoid generic AI copy#

Generic copy comes from generic input. When the brief says “write an email about our new collection”, the model has nothing to work with except the average of every new-collection email it has seen. These habits fix most of it.

  • Give one concrete detail per email. The yarn, the mill, why a coat has a two-way zip. The model builds around it.
  • Name the phrases to avoid. List the openers and words you never want (“In a world where”, “elevate your wardrobe”). Explain why: your customers read past them.
  • Ask for one idea, not five. An email that features one product and one reason to click reads like a person wrote it.
  • Cut the opening line. Drafts often warm up for a sentence before saying anything. Ask the model to start with the news.
  • Write the call to action yourself. “Shop the Harbor coat” is clearer than “Discover more”.
  • Keep a swipe file. Save the drafts you sent and the edits you made; paste them next time as examples.

For subject lines specifically, see email subject lines for e-commerce, and ready-made requests in ChatGPT prompts for email marketing.

Review checklist before you send#

  • Every price, discount code, date and end time matches the store.
  • Every product named exists, in the sizes and colors mentioned.
  • Links go to the right pages and carry your UTM tags if you use them.
  • Claims are true and you could show why (materials, origin, “best-selling”).
  • The subject line and preheader describe what is inside, with no fake “Re:” or false urgency.
  • Merge tags have a fallback, so nobody gets “Hi ,”.
  • The audience is people who opted in, with unsubscribed and bounced addresses excluded.
  • The footer has your postal address and a working unsubscribe link S4. The email footer checker can confirm both.
  • You have read it on a phone, and sent yourself a test.

An assistant that drafts versus one connected to your list#

Claude or ChatGPT on its own writes text. You then copy it into an email platform, rebuild the layout, pick the audience there and send. With an MCP connector, the assistant can work with the email tool directly: it reads your list, renders the real email and prepares the send, while the approval stays with you.

Writing with a chat assistant alone and with a connector such as Tellnod
StepAssistant aloneAssistant with Tellnod connected
DraftText you copy elsewhereAn email draft in your brand’s logo, colors and fonts
AudienceSuggestions you rebuild in another toolA segment from your description, with a count and unsubscribed contacts removed
PreviewYou imagine the layoutA preview card with the rendered email on desktop and mobile
TestManual, from another toolA test email to you, on request
SendDone in another toolA confirmation card with recipients, exclusions and send time; only you can press Confirm

With Tellnod connected, the same brief becomes a working session. You might type: “Draft an email to customers who bought knitwear last winter about the new merino crewnecks, no discount, link to the knitwear page.” The assistant drafts it and shows the preview card; you ask for changes in words; you ask for a test; then it prepares the send and the approval card shows who receives it and who is excluded and why. The assistant cannot press Confirm, and a scheduled send can be cancelled until it goes out.

The checks above still apply: Tellnod adds the unsubscribe link, postal address and consent handling, but you still verify the facts in the copy. Setup steps are in the guides for Claude and ChatGPT, or start on the connect page. Tellnod is free up to 500 contacts and 2,000 emails a month; see pricing.

FAQ#

Can AI write my marketing emails for me?

It can write a complete draft, subject lines and variants from a short brief, and rewrite them on request. You still need to check facts, prices and claims, choose the audience from people who opted in, and approve the send.

Is it legal to send marketing emails written by AI?

The rules apply to the email, not to who wrote it. In the US, CAN-SPAM requires accurate headers, honest subject lines, a postal address and a working opt-out, and the business remains responsible for the message S4. Other countries add consent rules.

Is Claude or ChatGPT better for writing marketing emails?

Both write good drafts when given a clear brief and examples. The quality of your brand context matters more than the model. Tellnod works in both, so you can use the one you already pay for.

Will emails written by AI go to spam?

Inbox placement depends mainly on sender authentication, complaint rates and honest content. Google asks bulk senders to keep the spam rate below 0.3% S5. See why emails go to spam.

Sources#

  1. [S1] Claude Docs: Prompting best practices, checked
  2. [S2] Claude Docs: Reduce hallucinations, checked
  3. [S3] FTC: Advertising FAQ’s: A guide for small business, checked
  4. [S4] FTC: CAN-SPAM Act: A compliance guide for business, checked
  5. [S5] Google Workspace Admin Help: Email sender guidelines, checked
  6. [S6] OpenAI API docs: Prompt engineering, checked