The best AI email writer for work

The best AI email writer is the one that fits where you write your email. If you want a general assistant for all kinds of drafts, ChatGPT or Claude work well. If you live in Gmail, Gemini is built in. If you want fixes inside every text box, Grammarly does that, and if you want drafts that come from your own documents, nerix is the option to test. All of them make mistakes, so read every email before you send it.

Prices checked in October 2026 and they change. Check the official pages: ChatGPT, Claude, Google AI plans, Google Workspace, Grammarly.

What to look for

A good AI email writer should do four things. It should draft from a few facts, match your tone, reply to an email you paste in and let you change the result quickly. Beyond that, check where your data goes, what the free plan limits and whether the draft can sit in your mail client or has to be copied across.

The options at a glance

ChatGPT

Good at: a flexible assistant for drafts, rewrites, shorter versions and tone changes. The free plan includes everyday text chat, with separate limits on tools such as file uploads and image generation.

Falls short: it lives in its own window, so you copy drafts into your mail client. Free access has limits that OpenAI says can change, and its model list changes often.

Price: Free, Go at 8 dollars a month in the US, Plus at 20 dollars, Business from 20 dollars per user a month billed annually (25 monthly).

Claude

Good at: drafts that read naturally, and long email threads you paste in for a summary and a reply. Claude's free plan includes chat on web, desktop and mobile, with file creation and connections to apps.

Falls short: same as ChatGPT: a separate window, so you copy the result across. Usage limits apply on every plan.

Price: Free, Pro at 17 dollars a month billed annually (20 monthly), Team standard seats at 20 dollars per user annually, according to Anthropic's page.

Gemini and Google Workspace

Good at: drafting where you already write. Google lists Gemini in Gmail on its AI Plus plan at 4.99 euros a month, and Workspace Business Starter lists a Gemini assistant in Gmail from 7 dollars per user a month on an annual plan.

Falls short: the free Gemini plan is a chat assistant, so the Gmail features come with a paid plan, and Starter has basic access with limits on advanced features. It suits Google users more than anyone else.

Grammarly

Good at: improving what you wrote, in any app or browser box: tone, clarity, correctness. The free plan lists 100 generative AI prompts a month, Pro lists 2,000.

Falls short: it is stronger at polishing than at drafting from a pile of facts. Plan details differ by region, and its Business plan is by quote, so check the page for your country.

Price: Free, Pro at 12 euros a month on Grammarly's euro page.

nerix

Good at: emails that depend on information you already have. In Email drafts, you tell nerix who the email is for and what it should say, or paste the one you received and ask for a reply. The draft opens beside the chat with To, Subject and the message, you change it in one click and you send it when you are ready. Because nerix can also chat with your sources, a reply to a client can draw on the contract or quote in your library, with the source shown. You choose the model, and nerix.ai runs on servers in the European Union today.

Falls short: Email drafts is in early access, so expect rough edges. nerix is a workspace, not a plug-in for your mail app, and it has fewer ways of working inside Gmail or Outlook than the suite tools do.

Price: Free for one person (3,000 credits a month, never charged beyond that), Plus at 15 euros a month. An email draft spends a little of the credits, and the app shows the price before you send. See pricing.

How to choose

• You want the most flexible assistant. ChatGPT or Claude, on the free plan first.
• You work in Gmail all day. Test Gemini where you write.
• Your drafts are mostly good and need polishing. Grammarly.
• Your replies depend on contracts, quotes and notes. Try nerix.
• Your emails are sensitive. Read the data terms of each plan, and prefer EU hosting if it matters to you.

Whichever you choose, the writing basics still decide whether emails get answered. Our guide to business emails that get read and answered covers them, and prompts that give usable first drafts covers the asking. Also read how to check AI answers before you send anything with numbers or promises in it.

Habits that make any tool better

The tool matters less than the brief. Give the reader, the goal and the one action you want, in a sentence. Paste a past email of yours so the tone matches, and name anything that must not appear, such as a price or a date you have not confirmed. Ask for two versions of different length and take the better one. Read the result aloud: if you would not say it, change it. Never let an AI add a fact you did not supply, and check names, dates and amounts every time before you press send.

The short version

The best AI email writer depends on where you write: ChatGPT and Claude for general drafting, Gemini for Gmail, Grammarly for polishing and nerix for replies built from your own documents. Every one has a free plan with limits, so start there. Always read the draft, check any fact and keep sensitive details out unless the data terms suit you.