ComparisonUpdated October 21, 2026

Best AI email assistant for Outlook: 5 options compared

If you already pay for Microsoft 365, start with Copilot in Outlook, because it is included in Microsoft 365 Personal, Family and Premium (on Family and Premium only for the subscription owner) and in the business plans that come with Copilot[1][2]. If you want an assistant that sorts your inbox in the background and prepares reply drafts, Fyxer and Inbox Zero are the obvious add-ons, while Superhuman replaces Outlook with its own fast email app[6][7][9][11]. Command Mail fits when your own agent, such as Claude, ChatGPT or Codex, should work with Outlook and other addresses under permissions you set[16].

Last checked: 2026-10-21. Command Mail is our product. All prices come from the vendors' own pages, retrieved on 2026-10-21.[1][2][5][8][10][16]

Updated: Fact-checked: About 10 min readAs Markdown

Contents
  1. How we compared, and our interest
  2. The five options at a glance
  3. Copilot in Outlook: built in and often already paid for
  4. Fyxer: sorts and drafts, you send
  5. Inbox Zero: open source and cheaper
  6. Superhuman: a different email app
  7. Command Mail: your own agent with limited permissions
  8. When another tool is the better choice
  9. When Command Mail fits
  10. Who Command Mail is not for
  11. How to set up and switch safely
  12. Further reading
  13. Frequently asked questions
  14. Sources

01How we compared, and our interest

We compared the options on five questions that matter for Outlook users. Where does the assistant work: inside Outlook, in the background on your mailbox, or in a different app? Which accounts does it support: Microsoft 365 work accounts, personal Outlook.com addresses, other providers? Who presses send, you or the software? What does it cost per month? Can your own AI agent connect over MCP?

Command Mail is our product, so it does not get first place by default. For most Outlook users a tool that works directly in the mailbox is the better fit, and we say for each vendor when it is the stronger choice. We did not run our own tests of the other products; every statement about them is based on the vendors' help and pricing pages.

02The five options at a glance

Copilot in OutlookFyxerInbox ZeroSuperhuman MailCommand Mail
Where it worksInside Outlook (Windows, Mac, web, iOS, Android)[3]In the background; results as Outlook folders and drafts[6]In the background on your existing mailbox[9]Its own email app instead of Outlook[11]Its own inbox; Outlook mail arrives by forwarding[16]
AccountsWork and personal Microsoft accounts, plus other accounts signed in to Outlook[3]Outlook and Gmail[5]Microsoft Outlook, Gmail, Google Workspace[18]Accounts hosted by Microsoft 365 or Google[11]Any address that can forward[16]
Who sendsYou, after keeping the draft[4]You; Fyxer never sends drafts automatically[7]You, after reviewing drafts[9]You; its MCP server can also send drafts directly[15]Your agent under your rules; sending from Pro[16]
Price per month (2026-10-21)Included in Microsoft 365 Personal $9.99, Family $12.99, Premium $19.99[1]; Business Standard with Copilot $23.50 per user, paid yearly[2]Free $0 (no automatic sorting or reply drafts), Pro $37 paid yearly or $49 monthly, Team $64 or $99[5]Starter $18, Plus $28, Professional $42 paid yearly; $20/$35/$50 monthly[8]Starter $30 or $300/year, Business $40 or $396/year[10]Free €0, Pro €19 for the first 100 paying accounts then €29, Team €39 per person[16]
Access for your own agentNot from the mail client itselfMCP on Team and above[5]MCP server[13]MCP server on Business and above[15]MCP, CLI and REST with separate permissions[16]

03Copilot in Outlook: built in and often already paid for

Copilot is the natural starting point because many Microsoft 365 subscriptions already include it. In the US, Microsoft 365 Personal costs $9.99 a month or $99.99 a year, Family $12.99 or $129.99, and Premium $19.99 or $199.99. On Family and Premium, only the person who set up the subscription can use Copilot; the other members get the apps without the AI features.[1]

For businesses, Microsoft lists Microsoft 365 Business Standard with Copilot at $23.50 and Business Premium with Copilot at $32 per user per month, paid yearly. If you already have a business plan, you can add Microsoft 365 Copilot Business; on the day we checked, the page showed a promotional price of $18 instead of $21 per user per month on annual billing.[2]

Microsoft says Copilot is available in Outlook for Windows, Mac, iOS, Android and the web, as long as connected experiences are not turned off in Outlook's privacy settings. With a personal subscription, Copilot also covers every account signed in to Outlook on the same device, including Outlook.com, work accounts, Gmail, Yahoo and iCloud. That cross-account sharing is not available in classic Outlook for Windows.[3]

When you draft, you stay in control. Copilot writes the text, you choose Keep or Insert, edit as needed and send it yourself. We found no description in Microsoft's help of Copilot in the mail client sending on its own. In new Outlook and Outlook on the web, drafting with Copilot does not support plain-text messages.[4]

In short, Copilot helps you write and summarize the message you have open. Microsoft does not describe it as a service that works through your inbox without being asked. For automatic sorting, Outlook still relies on rules and the Focused Inbox; Sort Outlook email automatically covers each Outlook version.[4]

04Fyxer: sorts and drafts, you send

Fyxer works in the background on your existing Outlook mailbox. It ranks incoming mail by priority: To respond or To do first, then FYI, then lower-priority groups such as Notification and Marketing. According to its help center, Fyxer creates one Outlook folder per category and also applies Outlook's color categories. Depending on your settings, a categorized message either stays in the inbox or moves to the matching folder.[6]

Fyxer writes reply drafts in your voice for messages that need an answer. They appear in your Drafts folder, or inside the thread if conversation view is on, which Fyxer recommends for Outlook. Its help center states that Fyxer never sends drafts automatically. If you already maintain your own categories, the Respect my categories setting leaves them alone, and Fyxer skips messages that an Outlook rule has already moved.[7][6]

The Pro plan costs $37 per person per month billed annually or $49 monthly; Team is $64 or $99. There is a free plan and a 14-day trial, but according to the pricing page automatic labeling starts with Pro and the free plan neither sorts your inbox nor drafts replies automatically. One seat covers several connected mailboxes of the same person, such as Gmail plus Outlook. The pricing page lists MCP access for Claude, ChatGPT and your own tools from the Team plan; it does not spell out what that access can do. For work accounts, Microsoft may ask for admin approval when you connect, and Fyxer's setup guide points to a separate article for that case. Fyxer's pricing page also lists SOC 2 Type II and ISO/IEC 27001, which matters if your company requires them.[5][14]

05Inbox Zero: open source and cheaper

Inbox Zero is an open-source AI assistant that connects directly to your Microsoft account. It triages incoming mail, drafts replies in your style, bulk-unsubscribes you from newsletters and tracks conversations that still need a reply. You keep reading and sending in Outlook; the vendor describes a flow in which you review drafts and send them yourself.[9]

Prices are $18 (Starter), $28 (Plus) and $42 (Professional) per user per month billed annually, or $20, $35 and $50 monthly, with a seven-day trial. Plus includes two email accounts per user. Because the code is public, you can also run Inbox Zero yourself. Its documentation covers bringing your own AI provider key and an MCP server that lets ChatGPT, Claude or Cursor search your inbox, create drafts and manage rules.[8][13]

Inbox Zero's home page advertises half the price of Superhuman. By list price, Inbox Zero Starter costs $18 a month paid yearly and Superhuman Starter $300 a year; paid monthly it is $20 against $30. Roughly half only holds against Superhuman Business at $40 a month. Price says nothing about quality, and the two products do different jobs[18][8][10].

06Superhuman: a different email app

Superhuman Mail replaces Outlook as your email app. You choose Sign in with Microsoft and from then on read your mail in Superhuman on desktop and phone. It is worth it mainly if you handle a lot of email from the keyboard and want a fast, carefully designed client.[11]

Its help center says it only supports accounts hosted by Google or Microsoft 365. Exchange servers that a company runs itself do not work, and there is no unified inbox across accounts; Superhuman suggests tabs instead. Starter costs $30 a month or $300 a year, Business $40 or $396. Auto Drafts, Ask AI and custom auto labels require Business, as does the MCP server for Claude, ChatGPT and other agents. Through that server an agent can send drafts directly, so Superhuman strongly advises requiring confirmation for each call.[12][11][10][15]

07Command Mail: your own agent with limited permissions

Command Mail is a separate inbox for all your addresses, built for your own AI agent to work in. You connect Claude, ChatGPT, Codex or Cursor over MCP and decide during the connection what the agent may do: read and sort, write drafts, send exactly the draft revision you approved, or send on its own within a daily limit. Each mailbox also gets an autonomy level, from read-only to auto.[16]

Outlook mail reaches Command Mail through automatic forwarding. Forwarding is not sync: whatever your agent sorts or archives in Command Mail does not change in Outlook. For a personal Outlook.com account you turn forwarding on in settings. In Microsoft 365 organizations the default policy often blocks forwarding to outside addresses; you then see error 5.7.520, and an admin has to allow it. The steps are in Connect Outlook to ChatGPT and Connect Outlook to Claude.[17]

The free plan covers one mailbox, the last 90 days, reading, search, sorting and drafts, without sending. Pro adds sending, up to ten mailboxes and full history for €19 a month for the first 100 paying Pro accounts, then €29; Team is €39 per person. Command Mail marks email content as untrusted data and flags suspected prompt injection. Agents do not write on their own to automated senders, mailing lists or no-reply addresses; that detection is heuristic and can miss cases.[16]

08When another tool is the better choice

  • Copilot if you already have Microsoft 365 and mainly want help writing and summarizing the message in front of you. No new account, no forwarding, no extra vendor processing your mail.[1][4]
  • Fyxer if you want a sorted inbox each morning and finished drafts in your Outlook Drafts folder without steering an agent yourself, plus meeting notes and scheduling.[6][7][5]
  • Inbox Zero if you want the same idea for less money, care about open code, or want to host it yourself.[8][13]
  • Superhuman if you want a new, very fast email app and your accounts live at Microsoft 365 or Google.[11]

Copilot, Fyxer and Inbox Zero work on the Outlook mailbox itself, so their drafts, folders or categories show up in Outlook. Superhuman also connects to the account directly, although its help says drafts from Outlook do not yet appear in Superhuman, and vice versa. Command Mail cannot offer either through forwarding[4][6][9][15].

09When Command Mail fits

Command Mail fits when your own agent should do the work and Outlook is one of several addresses. A common case is a personal Outlook.com address next to a Gmail account and a custom domain at a third provider. Your agent then sees everything in one inbox and gets only the permissions you grant.[16]

It also fits when you want tight control over sending. The agent saves a draft, you approve that exact revision, and only then may it send. Sending without approval is switched off when you connect and additionally requires the sending mailbox to be on auto.[16]

10Who Command Mail is not for

Command Mail is not for you if you want to stay in Outlook and see sorted folders there. Forwarding moves mail in one direction only, and replies go out from Command Mail, not from your Outlook Sent folder. It is also a poor fit if your admin does not allow external forwarding, or if you do not use an AI agent of your own and only want writing help. Copilot, Fyxer or Inbox Zero will serve you better.[16]

Command Mail is operated by FYN Labs LLC in the United States; according to the privacy policy, hosting and database run on Cloudflare and attachments are stored in Cloudflare's EU jurisdiction[19]. Command Mail does not claim certifications such as SOC 2 or ISO 27001.[16][5]

11How to set up and switch safely

Start with read access before you give any assistant write or send rights. Copilot works this way by design, because you keep every draft yourself. With Fyxer or Inbox Zero, spend a week watching how it sorts and checking its drafts before you rely on them. With Command Mail, approve only reading and drafts when you first connect, and turn on sending separately later.[4][7][16]

Also check who has to approve the connection. For Microsoft 365 work accounts, Fyxer and similar services may need admin consent, and the same applies to the external forwarding that Command Mail relies on.[14]

12Further reading

Reply to emails with AI explains how AI replies work in general. Connect Outlook to ChatGPT and Connect Outlook to Claude cover the direct routes. Command Mail's permissions and autonomy levels are in the docs.

You can start Command Mail for free and connect your agent afterwards.

Frequently asked questions

Is Copilot in Outlook free?

No, but it is included in Microsoft 365 Personal, Family and Premium; on Family and Premium only for the subscription owner. Businesses can buy plans with Copilot or add Copilot Business.

Does Copilot work with my Gmail account in Outlook?

With a personal Microsoft 365 subscription, yes, as long as the Gmail account is signed in to Outlook on the same device. Microsoft says this sharing does not apply in classic Outlook for Windows.

Which assistant sends email on its own?

Fyxer's help says it never sends on its own. Copilot hands drafts to you. Inbox Zero describes you reviewing and sending. Superhuman's MCP server can send drafts directly once you allow the tool. In Command Mail an agent sends without per-message approval only with the mail:send permission from a mailbox on auto; a draft you approved it sends with mail:send-approved on any level except read.

Does Superhuman work with my company's Exchange server?

Only if the account is hosted by Microsoft 365. Superhuman's help says it does not support self-hosted Exchange servers.

Can I keep using Outlook with Command Mail?

Partly. Outlook keeps receiving mail, but what your agent sorts, archives or answers in Command Mail does not show up in Outlook.

Sources

  1. Microsoft: Compare all Microsoft 365 products (US prices) microsoft.com, accessed
  2. Microsoft: Copilot for small business (US prices) microsoft.com, accessed
  3. Microsoft Support: Sharing Copilot in Outlook support.microsoft.com, accessed
  4. Microsoft Support: Draft an email message with Copilot in Outlook support.microsoft.com, accessed
  5. Fyxer: Pricing fyxer.com, accessed
  6. Fyxer Help Center: Outlook, folders vs categories support.fyxer.com, accessed
  7. Fyxer Help Center: How Fyxer drafts your emails support.fyxer.com, accessed
  8. Inbox Zero: Pricing getinboxzero.com, accessed
  9. Inbox Zero: AI email assistant for Outlook getinboxzero.com, accessed
  10. Superhuman Help Center: Pricing Plans help.superhuman.com, accessed
  11. Superhuman Help Center: Managing Accounts help.superhuman.com, accessed
  12. Superhuman Help Center: Troubleshooting Login Issues help.superhuman.com, accessed
  13. Inbox Zero Docs: index (Connect MCP, own API key) docs.getinboxzero.com, accessed
  14. Fyxer Help Center: Set up Fyxer in 2 minutes support.fyxer.com, accessed
  15. Superhuman Help Center: Superhuman Mail MCP Server help.superhuman.com, accessed
  16. Command Mail: llms.txt (plans, permissions, autonomy) commandmail.app, accessed
  17. Microsoft Support: Turn on or off automatic forwarding in Outlook.com support.microsoft.com, accessed
  18. Inbox Zero: home page getinboxzero.com, accessed
  19. Command Mail: Privacy policy commandmail.app, accessed
EN
DE