Best AI Email Writers: 9 Tools for Gmail and Outlook
· Updated October 30, 2026
The best AI email writer for most people is the one already inside your inbox. That means Gemini in Gmail if you use Google, or Microsoft 365 Copilot if you use Outlook. If you want a faster inbox, Superhuman and Shortwave are the top AI email apps.
This list covers tools that help you write and reply to everyday work email. It does not cover email marketing or cold outreach tools. Every price below was checked on vendor pages in October 2026.
What Is an AI Email Writer?
An AI email writer is a tool that drafts, replies to, shortens or polishes emails for you, based on a short prompt or the thread you are reading.
Most of these tools do a few of the same jobs:
- Draft from a prompt. You type "decline the meeting politely" and get a full email.
- Reply in context. The tool reads the thread and suggests a reply.
- Rewrite. It makes your draft shorter, friendlier or more formal.
- Summarize. It sums up long threads so you know what to answer.
There are three kinds of AI email tools. Some are built into Gmail or Outlook. Some are full email apps with AI inside. Others are general AI assistants, where you paste in a thread and copy the reply back.
The right kind depends on where you already work. If your company pays for Google Workspace or Microsoft 365, start with the built-in option.
Quick Comparison: 9 Best AI Email Writers
Gemini in Gmail is our top pick overall, followed by Microsoft 365 Copilot and Superhuman. Here is how all 9 compare on best use, starting price and where it works. Prices were checked in October 2026, so confirm them before you pay.
| Tool | Best For | Starting Price | Works In |
|---|---|---|---|
| Gemini in Gmail | Gmail users who want AI built into their inbox | Workspace Starter $7/user/mo | Gmail (web and mobile) |
| Microsoft 365 Copilot | Outlook users on Microsoft 365 | Copilot Business $21/user/mo yearly add-on | Outlook, Word, Teams |
| Superhuman | Busy professionals who live in email | Free; Pro $12/member/mo yearly | Gmail and Outlook accounts |
| Shortwave | Gmail teams that want an AI inbox agent | Business $30/seat/mo; 14-day trial | Gmail and Google Workspace |
| Spark Mail | Low-cost AI replies across many accounts | Free; Plus $10/mo or $99/yr | Gmail, Outlook, iCloud and more |
| Canary Mail | The cheapest paid AI email app | Free; Growth $36/yr | Gmail, Outlook, iCloud and more |
| Grammarly | Polishing tone in any email app | Free; Pro about $12/mo yearly | Browser, Gmail, Outlook, desktop |
| ChatGPT | Drafting tricky emails from a prompt | Free; Plus about $20/mo | Copy and paste into any app |
| Claude | Long, careful replies and rewrites | Free; Pro about $17/mo yearly | Copy and paste into any app |
What Makes a Good AI Email Generator?
A good AI email generator works where you already write, sounds like you, and is clear about what it reads from your inbox.
We weighed six things:
- Where it works. Inside Gmail or Outlook, as a separate app, or through copy and paste.
- Reply quality. Whether it uses the thread to write a reply that fits.
- Your voice. Whether you can set tone or teach it how you write.
- Privacy. What the vendor says it reads and whether your mail trains its models.
- Price. Whether prices are public and what one person really pays.
- Free access. Whether there is a free plan or a trial.
Tools ranked higher when they work inside your inbox and publish clear prices. For writing tools beyond email, see our list of the best AI writing tools.
Best AI Email Writers Built Into Gmail and Outlook
These two tools live inside the email apps most offices already use, so there is nothing new to install.
1. Gemini in Gmail: Best for Gmail users who want AI built into their inbox
Gemini is Google's AI assistant. In Gmail, it can write drafts, suggest replies and sum up long threads.
What it does well. Gemini sits right in the Gmail compose box. Click "Help me write," describe the email, and it drafts one. It can also polish a draft you started, or answer questions about your inbox from a side panel.
Key features:
- Help me write for new emails and replies
- Thread summaries
- Side panel that can search your inbox and Drive
- Included in Workspace Business plans
Pricing. Google's pricing page lists Gemini in Gmail in Business Starter and above. Starter is $7 a user a month. New customers saw an intro price of $3.50 for the first 3 months. Checked October 2026.
Privacy note. Google's Workspace privacy hub says Workspace does not use customer data to train models without the customer's permission. It also treats your prompts as customer data.
Best for: Teams and solo workers who already use Gmail with Google Workspace.
Limitations. Reports say Starter has tighter Gemini limits than higher plans. It only works in Gmail, not other email apps.
2. Microsoft 365 Copilot: Best for Outlook users on Microsoft 365
Microsoft 365 Copilot is Microsoft's AI assistant for Outlook, Word, Excel, Teams and other Office apps.
What it does well. In Outlook, Copilot can draft an email from a prompt, coach you on tone, and sum up long threads. Because it also works in Teams and Word, it can pull in context from your meetings and files.
Key features:
- Draft with Copilot in Outlook
- Email coaching on tone and clarity
- Thread summaries
- Works across Word, Excel, PowerPoint and Teams
Pricing. Copilot Business lists at $21 a user a month billed yearly, with a promo price of $18 shown in October 2026. Monthly billing is $25.20. It is an add-on, so each user also needs a Microsoft 365 plan. Checked October 2026.
Privacy note. Microsoft's Copilot privacy docs say prompts, responses and data accessed through Microsoft Graph are not used to train foundation models. Copilot only shows data you already have permission to see.
Best for: Companies that run on Outlook and Microsoft 365.
Limitations. It is the priciest option here once you add the base license. Small teams may pay for features they never use.
Best AI Email Apps
These email apps replace your inbox and add AI writing, so they suit people who spend hours a day in email.
3. Superhuman: Best for busy professionals who live in email
Superhuman is a fast email app for Gmail and Outlook accounts. It is now part of the same company as Grammarly.
What it does well. Superhuman is built for speed. It uses keyboard shortcuts and AI to help you clear your inbox fast. Its AI can write replies in your style and draft emails from a few words.
Key features:
- AI replies that learn from how you write
- Keyboard shortcuts for every action
- Split inbox to sort important mail
- Read status and reminders
Pricing. Superhuman's plans page now sells a suite with Mail, Grammarly, Coda and Go. Free costs $0. Pro is $12 a member a month billed yearly or $15 monthly. Business is $33 yearly or $40 monthly. Check which plan includes the Mail features you want. Checked October 2026.
Privacy note. Superhuman connects to your full mailbox to run as your email app. Read its privacy policy for how its AI handles your mail.
Best for: Founders, sales leads and managers who handle a lot of email.
Limitations. The plan names cover a whole suite, so it is not always clear what you get in Mail. You need to switch to its app to get the benefit.
4. Shortwave: Best for Gmail teams that want an AI inbox agent
Shortwave is an AI email app built for Gmail and Google Workspace accounts.
What it does well. Shortwave has an AI assistant that can search your inbox, answer questions about your mail and write replies. It also groups emails into bundles so you can clear them faster.
Key features:
- AI assistant that searches and writes
- Draft replies using thread context
- Bundles and to-do style inbox
- 14-day free trial
Pricing. Business is $30 a seat a month, Premier is $45 and Max is $120. A 14-day free trial is offered. Checked October 2026.
Privacy note. Shortwave's AI reads your Gmail to search and draft. Check its privacy page for how that data is stored and processed.
Best for: Gmail users and small teams who want AI to do more than draft.
Limitations. It works with Gmail and Google Workspace, not Outlook. Paid plans cost more than Gemini in Gmail.
5. Spark Mail: Best for low-cost AI replies across many accounts
Spark is an email app from Readdle. It works with Gmail, Outlook, iCloud and other accounts in one inbox.
What it does well. Spark +AI can write, rephrase and shorten emails. It also sums up threads. Spark puts all your accounts in one place, which helps if you juggle work and personal mail.
Key features:
- Spark +AI writing and replies
- Thread summaries
- Smart inbox across many accounts
- AI meeting notes on paid plans
Pricing. Free costs $0 with only a limited AI preview. Plus is $10 a user a month or $99 a year. Pro is $20 a month or $199 a year. Checked October 2026.
Privacy note. Spark's pricing page says Spark +AI is turned off by default, so you choose when to use it. AI use also has a monthly quota.
Best for: People with several email accounts who want AI at a fair price.
Limitations. The free plan has very little AI. AI features have monthly limits on paid plans.
6. Canary Mail: Best for the cheapest paid AI email app
Canary Mail is an email app that focuses on privacy and security, with an AI copilot on paid plans.
What it does well. Canary's AI Copilot helps you write, reply and sum up emails. It works with Gmail, Outlook, iCloud and other accounts. Its Pro+ plan adds encryption and phishing protection.
Key features:
- AI Copilot for writing and replies
- Email summaries
- PGP encryption and phishing checks on Pro+
- Free plan for the core inbox
Pricing. Free costs $0. Growth is $36 a year, about $3 a month, and adds AI Copilot. Pro+ is $100 a year. Lifetime options are offered, but prices were not listed. Checked October 2026.
Privacy note. Canary's FAQ says your emails are not used to train AI models. It says AI features are optional and can be turned off.
Best for: Budget users and privacy-minded people who want AI in a full email app.
Limitations. There are no monthly plans, only yearly or lifetime. The free plan does not include the AI Copilot.
Best AI Assistants to Write Emails
These tools are not email apps, but they help you write and polish emails in any inbox.
7. Grammarly: Best for polishing tone in any email app
Grammarly is a writing assistant that checks and rewrites text in your browser, email and documents.
What it does well. Grammarly works inside Gmail, Outlook and most web apps. It fixes grammar, flags tone and can rewrite a sentence to sound clearer or kinder. Its AI can also draft short replies.
Key features:
- Grammar, clarity and tone checks
- AI rewrites and short drafts
- Works in browsers, Gmail, Outlook and desktop apps
- Free plan
Pricing. There is a free plan. Pro is $12 a month billed yearly, per Grammarly's plans page. Checked October 2026.
Privacy note. Grammarly reads the text you type where it is turned on. You can turn it off for any site or app.
Best for: People who write their own emails and want them cleaner.
Limitations. It does not read whole threads like an inbox tool does. Most AI features sit on paid plans.
8. ChatGPT: Best for drafting tricky emails from a prompt
ChatGPT is OpenAI's AI assistant. Many people use it to write hard emails, like complaints, apologies or salary talks.
What it does well. You paste in a thread, explain what you want, and ChatGPT writes a reply. You can ask for more versions or a different tone. Custom instructions help it match your style.
Key features:
- Drafts and replies from a short prompt
- Tone changes on request
- Custom instructions for your style
- Free plan with limits
Pricing. There is a free plan. Plus is widely reported at about $20 a month. Confirm on OpenAI's page, which we could not load in October 2026.
Privacy note. ChatGPT only sees what you paste in. Check OpenAI's data controls for how your chats are used.
Best for: Anyone who needs help with a few hard emails a week.
Limitations. Copying and pasting is slow for a busy inbox. Do not paste private data your company forbids.
9. Claude: Best for long, careful replies and rewrites
Claude is Anthropic's AI assistant. It is good at careful writing and long threads.
What it does well. Claude can read a long email chain and write a calm, clear reply. It is useful for sensitive emails where wording matters. Projects let you save examples of your writing for repeat use.
Key features:
- Handles long threads and documents
- Rewrites in a chosen tone
- Projects to store style examples
- Free plan with limits
Pricing. Free costs $0. Pro is about $17 a month billed yearly or $20 monthly. Checked October 2026.
Privacy note. Claude only sees what you paste in or connect. Check Anthropic's privacy settings for how your chats are used.
Best for: People who write long or delicate emails.
Limitations. Like ChatGPT, it needs copy and paste unless you set up a connection. Usage limits apply on every plan.
How Should You Choose an AI Email Writer?
Choose based on which email app you use, how much email you handle, and how much you want to spend.
- Your team uses Gmail: Gemini in Gmail, since it comes with Workspace.
- Your team uses Outlook: Microsoft 365 Copilot.
- You live in email all day: Superhuman or Shortwave.
- You have many accounts: Spark or Canary Mail.
- You want the lowest cost: Canary Mail Growth at $36 a year.
- You only want cleaner writing: Grammarly.
- You write a few hard emails a week: ChatGPT or Claude.
If grammar is your main worry, see our list of the best AI grammar checkers. For more general assistants, see the best AI chatbots.
How We Evaluated These AI Email Writers
This list is built from each vendor's official pricing pages, product docs and privacy statements, checked in October 2026.
Tools were ranked on where they work, reply quality features, voice settings, privacy statements, price and free access. This list is not based on hands-on testing. Try the free plans and trials on your own inbox before you pay.
Is There a Free AI Email Writer?
Yes. ChatGPT, Claude and Grammarly all have free plans that can write emails, and Spark and Canary Mail have free email apps.
Each free plan has limits:
- ChatGPT and Claude: free, with daily caps, and you copy and paste.
- Grammarly: free grammar checks, with most AI on paid plans.
- Spark: free app with only a limited AI preview.
- Canary Mail: free app, but the AI Copilot starts on Growth at $36 a year.
If you already pay for Google Workspace or Microsoft 365, check what AI your plan includes. Gemini in Gmail comes with every Workspace Business plan.
Is It Safe to Let AI Read Your Email?
It can be, if you pick a vendor that says clearly what it reads and does not train on your mail, and your company allows it.
Here is what to check before you connect an inbox:
- Training. Does the vendor say your emails are not used to train its models?
- Access. Does it read your full mailbox, or only what you send it?
- Controls. Can you turn AI off, or turn off training in settings?
- Company rules. Does your employer allow outside apps on work email?
Built-in tools like Gemini and Copilot keep data inside the service your company already uses. Copy and paste tools only see what you give them. For a wider look, read our guide on whether AI chatbots are safe.
The Bottom Line
Gemini in Gmail is the best AI email writer for Gmail users, and Microsoft 365 Copilot is the best for Outlook users.
Superhuman and Shortwave suit people who live in email. Spark and Canary Mail are the best low-cost apps. Grammarly is best for polish, and ChatGPT or Claude help with hard one-off emails.
Next steps: Check which AI your current email plan already includes, then try one app on a week of real mail. For more options, see our full list of the best AI writing tools.
Comparing every AI writer?
See our full ranking of the best AI writing tools for drafts, emails, docs and marketing copy.
Frequently Asked Questions
What is the best AI email writer?
For most people, it is the one built into their inbox. That is Gemini in Gmail for Google users and Microsoft 365 Copilot for Outlook users. Superhuman is a strong pick for heavy email users.
Can I use AI to write emails for free?
Yes. ChatGPT, Claude and Grammarly have free plans. Spark and Canary Mail have free apps, but their AI is limited or paid. Free plans have daily or monthly limits.
Does Gmail have an AI email writer?
Yes. Gemini in Gmail offers "Help me write" and suggested replies. Google lists it in every Workspace Business plan, starting with Business Starter.
Does Outlook have an AI email writer?
Yes. Microsoft 365 Copilot can draft and coach emails in Outlook. Copilot Business lists at $21 a user a month billed yearly, on top of a Microsoft 365 plan.
Is ChatGPT good for writing emails?
Yes, for one-off or tricky emails. You paste in the thread and ask for a reply. For a busy inbox, a built-in tool or AI email app saves more time.
What is the cheapest AI email app?
Canary Mail Growth is the cheapest paid AI email app on this list at $36 a year. Spark Plus is next at $99 a year.