Short answer: if your company already licenses Microsoft 365 Copilot, start with Copilot in Outlook. It summarises and drafts when you ask. If you want drafts prepared in the background for new mail, in your own Outlook, and you review before anything is sent, look at Jace or Fyxer. If you want a different, faster email app on top of Microsoft 365, look at Superhuman or Spark. If you want one AI agent for email plus meetings and other tools, look at Lindy. Two popular tools, Shortwave and Gmelius, do not support Microsoft 365 mailboxes, so they are left out.
This guide was compiled on 9 November 2026. We make Jace. Read the linked vendor pages yourself, because prices and features in this category change every few months.
How we chose and compared
- Must work with Outlook. Each tool connects to Outlook or Microsoft 365 mail according to its own pages. Tools that only support Gmail are left out.
- Sources: each vendor's own pricing page, product page or help centre, opened on 9 November 2026 and linked at the end. Lindy facts were checked on 7 November 2026 for our wider comparison. No review sites or affiliate lists.
- What we did not do: timed tests or benchmarks. We don't publish "hours saved" numbers. Where a vendor makes a claim, we say so.
- What we compared: whether it drafts without being asked and whether it can send without you. We also noted where you work (Outlook itself or another app) and the list price for one person.
Quick picks for Outlook
| Tool | Best for | Where you work | Drafts without being asked | List price for one person |
|---|---|---|---|---|
| Copilot in Outlook | Microsoft 365 organisations already paying for Copilot | Outlook | No, on request | Copilot Business from $18 per user a month billed yearly |
| Jace | Drafts waiting in Outlook, reviewed before sending | Outlook, plus the Jace web app | Yes, for the labels you choose | $20 a month billed yearly, $25 monthly |
| Fyxer | Drafts plus a meeting notetaker | Outlook | Yes | Free plan. Pro $37 billed yearly, $49 monthly |
| Superhuman | A fast email app, or an assistant inside Outlook | Outlook (Email Assistant) or the Superhuman app | Yes, Email Assistant | Pro $12 billed yearly, $15 monthly |
| Lindy | One AI agent for email and other work | Lindy, connected to Outlook | Yes, per its setup | Credit-based, see Lindy pricing |
| Spark | A cross-platform email app with AI drafts | The Spark app | Auto-Drafts on Pro | Free. Pro $20 a month or $199 a year |
The 6 options
1. Copilot in Outlook
Microsoft's assistant sits inside Outlook. Its FAQ covers summarising threads, drafting from a prompt and coaching on tone. Many features need a Microsoft 365 Copilot licence. Microsoft lists Copilot Business from $18 per user a month billed yearly (a promotional price, normally $21) on its Copilot Business page.
- Fits: organisations standardised on Microsoft 365 that want AI across Outlook, Word and Teams.
- Watch-outs: it drafts when you ask, not in the background for new mail.
- Compared in depth: Jace vs Copilot in Outlook.
2. Jace
Jace connects to Outlook on Microsoft 365 or Outlook.com and works in the background. It labels new mail, with labels synced as Outlook categories. It writes reply drafts for the labels you pick, such as Needs Reply, and saves them to your Outlook Drafts folder. Drafts use the full thread, attachments, your calendar, your rules and your writing style (Drafting). Threads in Waiting get a follow-up draft after 3 days without a reply. Flows let you write automations in plain English, and Jace connects to Slack, OneDrive, HubSpot and other tools.
- Fits: people who answer their own client email from Outlook, such as lawyers and consultants.
- Watch-outs: no native mobile app yet (drafts show in Outlook on your phone). No shared inbox or team assignments.
- Price: Plus $25 a month or $20 billed yearly, with 2 inboxes. Pro $50 or $40 billed yearly, with 8 inboxes. 7-day free trial (pricing).
- Setup and permissions: Jace for Outlook.
3. Fyxer
Fyxer signs up with Google or Microsoft, sorts the inbox, drafts replies in your tone and takes meeting notes. Its pricing page lists a Free plan, Pro at $37 per person a month billed yearly or $49 monthly, and Team at $64 or $99. Paid plans have a 14-day trial. Fyxer says one seat covers both a Gmail and an Outlook account.
- Fits: people who want email drafting and meeting notes in one product.
- Compared in depth: Jace vs Fyxer.
4. Superhuman
Superhuman launched Email Assistant on 3 November 2026. It runs inside Gmail and Outlook, labels mail, drafts replies in your voice, reminds you about unanswered threads and archives low-priority mail. Superhuman says it never sends for you. It is part of Pro at $12 a month billed yearly or $15 monthly. Superhuman Mail, the separate email app, is in Business at $33 or $40 (plans).
- Fits: people who want the four basics at a low price, or a keyboard-first email app.
- Compared in depth: Superhuman Email Assistant vs Jace.
5. Lindy
Lindy is a general AI assistant for work. Email is one of its jobs: it connects to Gmail or Outlook, drafts replies in your voice and handles scheduling, alongside meetings and many integrations. Pricing is credit-based (Lindy pricing).
- Fits: people who want one agent across email and other tools and are happy to set it up.
- Compared in depth: Jace vs Lindy.
6. Spark
Spark by Readdle is an email app that supports Outlook and Exchange accounts alongside Google, iCloud and IMAP. Its pricing page lists a Free plan, Plus at $10 a month or $99 a year and Pro at $20 a month or $199 a year. Auto-Drafts and Autopilot rules are on Pro.
- Fits: people happy to switch to a new app on every device.
- Compared in depth: Jace vs Spark.
Left out, and why
- Shortwave supports Gmail and Google Workspace only. Its docs say Microsoft 365 and Exchange are not supported (our Shortwave comparison).
- Gmelius is built for Google accounts (our Gmelius comparison).
How to choose for Outlook
- Already paying for Copilot? Use it for summaries and on-request drafts for a week. If you still open every thread to a blank reply, add a background assistant.
- Want to stay in Outlook? Pick an assistant that writes into your Outlook Drafts folder: Jace, Fyxer or Superhuman's Email Assistant.
- Need email to update other tools? Check whether the assistant connects to your CRM, Slack or file storage. Jace does this through Flows and integrations.
- Check your IT policy. Microsoft 365 admins can require admin approval before users connect third-party apps. Ask your admin before you connect a work mailbox.
FAQ
What is the best AI email assistant for Outlook? It depends on what you want it to do. Copilot in Outlook is the default if your company already licenses it. For drafts prepared in the background inside Outlook, Jace and Fyxer are built for that. For a new email app, Superhuman or Spark.
Does Copilot in Outlook draft replies automatically? No. Microsoft describes Copilot drafting as something you start, by prompt. It doesn't prepare drafts for new mail in the background.
Which AI email assistants work with Outlook.com, not just Microsoft 365? Jace works with both Outlook on Microsoft 365 and Outlook.com. Check each other vendor's sign-up page for personal Outlook.com accounts.
Does Jace send emails from Outlook without my approval? Not by default. Drafts land in your Outlook Drafts folder. Auto-send stays off unless you turn it on for a specific label or Flow, and Jace warns you first.
Is there a free AI email assistant for Outlook? Fyxer and Spark list free plans. Jace has a 7-day free trial, not a free plan.
Try Jace in your Outlook inbox
Connect Outlook and see Jace's drafts on your real threads for 7 days, with auto-send off. Start your free Jace trial, or read how Jace works with Outlook first. Using Gmail too? See the best AI email assistant for Gmail and Jace for Gmail. For the full field, see the best AI email assistants in 2026.
Sources (checked 9 November 2026 unless noted)
- Microsoft: Entra user consent settings, Copilot in Outlook FAQ, Microsoft 365 Copilot Business
- Fyxer: pricing
- Superhuman: Email Assistant, plans
- Lindy: pricing (checked 7 November 2026)
- Spark: homepage, pricing
- Jace: pricing, Drafting, Jace for Outlook
