AI Email Assistants for Outlook: Copilot and Third-Party Tools
If you want an AI email assistant for Outlook, the built-in option is Microsoft Copilot in Outlook. Third-party tools matter more when you need stronger writing help, shared-inbox workflows, or a more proactive assistant layer.
Short answer: If you want an AI email assistant for Outlook, the built-in option is Microsoft Copilot in Outlook. [ 2 , 3 ] Third-party tools matter more when you need stronger writing help , shared-inbox workflows, or a more proactive assistant layer.
What’s new
Microsoft kept expanding Copilot in Outlook in 2026, adding new inbox, follow-up, and calendar experiences and broadening support across more account types and shared or delegated mailbox setups. [ 1 , 9 , 10 ]
This guide compares Microsoft’s own Outlook AI with third-party tools that work inside Outlook or connect tightly enough to Outlook accounts to change day-to-day work. It is meant for solo users, managers, and shared-inbox teams who want a fast, honest shortlist, not a giant catalog.
The main trade-off is native convenience versus specialized depth. If you already have the right Microsoft 365 plan, Copilot is usually the first place to look. Third-party tools make more sense when you need stronger writing control, Outlook-specific email workflows, shared ownership, or more proactive automation.
Key takeaways
- Copilot in Outlook is the built-in AI option for Outlook. [ 2 , 3 ]
- If you already have the right Microsoft 365 plan, Copilot is usually the first place to look. [ 2 , 5 ]
- MailMaestro is the Outlook-first pick for people who want a dedicated add-in for email work. [ 11 , 12 ]
- Grammarly fits people who mainly want better writing quality, tone control, and rewrites in Outlook and beyond. [ 13 , 14 ]
- Hiver is the best fit here for shared inbox operations with owners, SLAs, internal notes, and reporting. [ 16 , 17 , 18 ]
- Fyxer is the more assistant-style option for proactive sorting, voice-matched drafts, and meeting help. [ 19 , 20 ]
- Before rollout, check account type, Outlook version, mailbox type, license, and permissions. [ 2 , 7 , 10 , 11 , 19 ]
Best Outlook AI assistants at a glance
If you just want the shortlist: start with Copilot if you already have the right Microsoft 365 plan. Choose MailMaestro for an Outlook-first add-in, Grammarly for writing quality, Hiver for shared-inbox operations, and Fyxer for more proactive sorting and meeting help.
| Tool | Best for | What it does best | Biggest catch | Typical cost |
|---|---|---|---|---|
| Copilot in Outlook (work) | Teams already on Microsoft 365 | Native summaries, drafting, and meeting help; with the fuller license it can also pull from chats and work data. [ 2 , 3 ] | Feature depth still varies by plan, license label, and rollout timing. [ 2 , 4 ] | Microsoft’s public business page starts around $18 per user/month, with higher-priced bundles above that. Public pricing can change. [ 5 ] |
| Copilot in Outlook (personal) | Microsoft 365 home users who want built-in AI | Native Outlook drafting and summaries, plus cross-account use in supported Outlook apps when you sign in with an eligible account. [ 7 , 9 ] | Family AI benefits in desktop apps are owner-only, and usage limits apply. [ 6 , 8 ] | Microsoft 365 Personal is $9.99/month or $99.99/year on the public page; Family is $129.99/year. Public pricing can change. [ 6 ] |
| MailMaestro | People who want a dedicated Outlook add-in for email work | Thread and attachment summaries, AI replies, labels, reminders, and Outlook-first workflows. [ 11 , 12 ] | The free tier is limited, and the app needs broad mailbox access to do its job. [ 11 , 12 ] | Free plan available; paid starts at $12 per seat/month billed annually or $15 monthly. Public pricing can change. [ 12 ] |
| Grammarly | People who mainly want better writing in Outlook | Rewrites, tone control, and a writing layer that follows you beyond Outlook into many other apps. [ 13 , 14 ] | It is a writing assistant first, and the old Microsoft Office add-in is being retired. [ 15 ] | Free plan available; Pro is $12 per member/month billed annually or $30 monthly. Public pricing can change. [ 13 ] |
| Hiver | Support, finance, and operations teams in shared Outlook inboxes | Shared inbox ticketing, routing, SLAs, analytics, and AI Copilot for team replies and triage. [ 16 , 18 ] | This is closer to a service platform than a small Outlook add-in. [ 16 , 17 ] | Hiver’s public Omni pricing runs from $25/$35 to $85/$95 per user/month depending on plan and billing. Public pricing can change. [ 17 ] |
| Fyxer | Users who want proactive sorting plus meeting help | Voice-matched drafts, smart inbox organization, meeting notes, and stronger assistant-style automation. [ 19 , 20 ] | To be useful, it needs deep mailbox context, so permission review matters. [ 19 ] | Starter is $30 monthly or $22.50 billed annually; Professional is $50 monthly or $37.50 billed annually. Public pricing can change. [ 20 ] |
Copilot in Outlook (work)
- Best for
- Teams already on Microsoft 365
- What it does best
- Native summaries, drafting, and meeting help; with the fuller license it can also pull from chats and work data. [ 2 , 3 ]
- Typical cost
- Microsoft’s public business page starts around $18 per user/month, with higher-priced bundles above that. Public pricing can change. [ 5 ]
Copilot in Outlook (personal)
- Best for
- Microsoft 365 home users who want built-in AI
- What it does best
- Native Outlook drafting and summaries, plus cross-account use in supported Outlook apps when you sign in with an eligible account. [ 7 , 9 ]
- Typical cost
- Microsoft 365 Personal is $9.99/month or $99.99/year on the public page; Family is $129.99/year. Public pricing can change. [ 6 ]
MailMaestro
- Best for
- People who want a dedicated Outlook add-in for email work
- What it does best
- Thread and attachment summaries, AI replies, labels, reminders, and Outlook-first workflows. [ 11 , 12 ]
- Biggest catch
- The free tier is limited, and the app needs broad mailbox access to do its job. [ 11 , 12 ]
- Typical cost
- Free plan available; paid plans start at $12 per seat/month billed annually or $15 monthly. Public pricing can change. [ 12 ]
Grammarly
- Best for
- People who mainly want better writing in Outlook
- What it does best
- Rewrites, tone control, and a writing layer that follows you beyond Outlook into many other apps. [ 13 , 14 ]
- Biggest catch
- It is a writing assistant first, and the old Microsoft Office add-in is being retired. [ 15 ]
- Typical cost
- Free plan available; Pro is $12 per member/month billed annually or $30 monthly. Public pricing can change. [ 13 ]
Hiver
- Best for
- Support, finance, and operations teams in shared Outlook inboxes
- What it does best
- Shared inbox ticketing, routing, SLAs, analytics, and AI Copilot for team replies and triage. [ 16 , 18 ]
- Typical cost
- Hiver’s public Omni pricing runs from $25/$35 to $85/$95 per user/month depending on plan and billing. Public pricing can change. [ 17 ]
Fyxer
- Best for
- Users who want proactive sorting plus meeting help
- What it does best
- Voice-matched drafts, smart inbox organization, meeting notes, and stronger assistant-style automation. [ 19 , 20 ]
- Biggest catch
- To be useful, it needs deep mailbox context, so permission review matters. [ 19 ]
- Typical cost
- Starter is $30 monthly or $22.50 billed annually; Professional is $50 monthly or $37.50 billed annually. Public pricing can change. [ 20 ]
Check these before you buy: [ 2 , 4 , 7 , 10 , 11 , 19 ]
- Your account type: work, school, or personal
- Your Outlook version or app: new Outlook, classic Outlook, or another supported Outlook app
- Your mailbox type: primary, shared, or delegated
- Your license: included access versus a fuller Copilot or paid add-on plan
- Your permissions review: how much mailbox and calendar access the tool needs
How we chose these Outlook AI tools
We kept this Outlook AI list short on purpose. Every option here has clear Outlook relevance plus current public pricing or licensing guidance. We separated Microsoft’s built-in Outlook AI from third-party tools because they solve different problems. If you want the least setup friction, start with Copilot. If you need stronger writing controls, shared ownership, SLAs, or proactive sorting, the third-party options move up quickly.
Rule of thumb: if you only need help wording emails, do not pay shared-inbox prices. If Outlook is really a team queue, do not expect a grammar tool to solve it.
Built-in Outlook AI: Microsoft Copilot
For Microsoft’s own Outlook AI, the biggest split is work versus personal licensing, plus whether you use new Outlook or classic Outlook. Do not assume every Microsoft 365 user gets the same Copilot experience. [ 2 , 3 , 7 ]
Microsoft Copilot in Outlook for work
Best for: Microsoft 365 teams that want native Outlook AI before adding anything else.
- Key strength: It covers the core Outlook jobs inside the app you already use: thread summaries, draft replies, triage help, and meeting or event assistance. [ 3 ]
- Key strength: Eligible work accounts can use Copilot Chat in Outlook even without the add-on license. The fuller Copilot license expands what chat can use across your inbox, calendar, meetings, chats, and enterprise data. [ 2 , 4 ]
- Key strength: Microsoft kept improving the Outlook side in 2026, including writing coaching and broader shared or delegated mailbox chat support. [ 9 , 10 ]
- Biggest drawback: Two coworkers can both “have Copilot in Outlook” and still get meaningfully different depth because of plan, license, and rollout timing. [ 2 , 4 ]
- Watch-out: Signed or encrypted mail, some labeled mail, and some mailbox types still have limits. Shared or delegated mailboxes also still miss some direct actions, including triage, sending on your behalf, and meeting updates. [ 3 , 10 ]
- Price / effort: Depending on your Microsoft 365 plan, some Copilot Chat access may already be included. On Microsoft’s public business page, listed Copilot offers start around $18 per user/month, with higher-priced bundles above that. Public pricing can change. [ 2 , 5 ]
Microsoft Copilot in Outlook for personal or family use
Best for: home users who already pay for Microsoft 365 and want built-in Outlook AI.
- Key strength: Copilot is included in qualifying Microsoft 365 subscriptions for individuals and families, so it can be the simplest zero-extra-tool option for personal Outlook use. [ 4 , 6 ]
- Key strength: In supported Outlook apps, an eligible Copilot sign-in can make Copilot available across connected accounts on the same device, including third-party accounts added to Outlook. [ 7 ]
- Key strength: In June 2026, Microsoft added drafting and refining emails in Copilot Chat using personal Microsoft accounts in new Outlook for Windows. [ 9 ]
- Biggest drawback: The Family plan is not a shared AI pass for everyone in the household. Desktop-app AI benefits are owner-only, and AI credits or usage limits still apply. [ 6 , 8 ]
- Watch-out: Cross-account Copilot sharing is not available in classic Outlook for Windows, and Connected Experiences must be turned on. [ 7 ]
- Price / effort: Microsoft 365 Personal is $9.99/month or $99.99/year on Microsoft’s public page; Family is $129.99/year. Public pricing and AI limits can change. [ 6 , 8 ]
Third-party AI email assistants that stay close to Outlook
These tools stay closest to the individual email workflow. They make more sense than a bigger service layer when your main goal is better drafting, summaries, or message handling inside Outlook.
MailMaestro
Best for: people who want a dedicated Outlook-first AI add-in for faster email handling.
- Key strength: It is built specifically for Outlook and works across Outlook on Mac, Windows, and web, so you stay in the same email flow. [ 11 ]
- Key strength: It goes beyond generic rewrites with thread and attachment summaries, Auto Label, reminders, and smart meeting scheduling. [ 11 , 12 ]
- Key strength: It leans into email-specific drafting and voice control rather than acting like a general chat box pasted into Outlook. [ 11 ]
- Biggest drawback: The free plan is mostly a sampler. The features that make it feel like a real assistant sit on the paid tier. [ 12 ]
- Watch-out: Microsoft’s marketplace listing says the app can read or modify mailbox items and access message or calendar details, including attachments. That is normal for this category, but it matters for admin review. [ 11 ]
- Price / effort: Free plan available. Paid plans start at $12 per seat/month billed annually or $15 monthly, with enterprise pricing on request. Public pricing can change. [ 12 ]
Grammarly
Best for: people who mainly want cleaner, faster writing in Outlook rather than inbox automation.
- Key strength: It is strong on the sentence-level work that slows people down in email: rewriting, tone control, clarity fixes, and AI prompts for first drafts. [ 13 ]
- Key strength: It works across Outlook and many other apps, so you are paying for one writing layer instead of an Outlook-only add-in. [ 13 , 14 ]
- Key strength: It is also a better fit if your work crosses languages, because Grammarly positions multilingual writing support as a core feature. [ 13 ]
- Biggest drawback: It helps at the sentence and paragraph level, not the inbox-operations level. If you want triage, ticketing, or follow-up workflows, it will feel thin.
- Watch-out: Grammarly is retiring Grammarly for Microsoft Office; that add-in will stop receiving security updates, feature updates, and technical support, and Grammarly points users to Grammarly for Windows instead. [ 15 ]
- Price / effort: Free plan available. Grammarly Pro is $12 per member/month billed annually or $30 monthly. Public pricing can change. [ 13 ]
Outlook AI for shared inboxes and proactive workflows
These options go beyond drafting. They make more sense when Outlook is part of a team queue or when you want more proactive help around email and meetings.
Hiver
Best for: support, finance, and operations teams treating Outlook as a shared queue, not just a personal inbox.
- Key strength: Hiver turns Outlook shared inboxes into trackable queues with owners, tags, shared drafts, internal notes, SLAs, and analytics. [ 16 ]
- Key strength: Hiver AI Copilot is built for team support work: drafting replies, surfacing answers, suggesting next steps, and helping agents work faster in context. [ 18 ]
- Key strength: On Hiver’s current Omni pricing page, AI Copilot and AI Agents are listed starting from the Growth plan upward. That matters if you want shared-inbox tooling and AI help in one plan instead of stitching together separate tools. [ 17 ]
- Biggest drawback: This is heavier than a personal email assistant. If your problem is just writing faster in your own inbox, it is probably too much.
- Watch-out: Hiver says it does not replace Outlook, but it does pull Outlook shared emails into Hiver’s own workspace. In practice, that means a service-platform experience, not a small compose-side add-in. [ 16 , 17 ]
- Price / effort: Hiver’s current public Omni pricing shows Growth at $25/$35, Pro at $55/$65, and Elite at $85/$95 per user/month depending on annual versus monthly billing. Voice is an extra add-on. Public pricing can change. [ 17 ]
Fyxer
Best for: executives, founders, and professionals who want a more proactive assistant layer on top of Outlook.
- Key strength: Fyxer focuses on the assistant-style jobs people actually want: drafting replies in your voice plus email categorization and smart inbox organization. [ 19 , 20 ]
- Key strength: It also includes meeting notetaking and AI summaries, which makes it more useful if email and meetings are a single workflow for you. [ 19 , 20 ]
- Key strength: The Professional tier adds multiple inboxes and calendars, team scheduling across time zones, chat over your inbox and meeting notes, and HubSpot integration. [ 20 ]
- Biggest drawback: It is pricier than simple writing-only tools, so it makes most sense only if you want proactive help, not just cleaner wording.
- Watch-out: Fyxer says that once you connect it, it starts reading incoming messages to categorize them and draft replies. For many teams that is the point, but it also means permission review matters before rollout. [ 19 ]
- Price / effort: Current public pricing shows Starter at $30/user/month or $22.50 billed annually, Professional at $50/user/month or $37.50 billed annually, and Enterprise as custom. Public pricing can change. [ 20 ]
Which Outlook AI assistant is best for you?
- Your company already lives in Microsoft 365: Copilot in Outlook for work. Start with the tool that already knows your Microsoft context before paying for another layer. [ 2 , 5 ]
- You already pay for Microsoft 365 at home: Copilot in Outlook for personal use. It is the cleanest built-in option, but check owner-only rules and AI limits first. [ 6 , 8 ]
- You want a dedicated Outlook add-in for email work: MailMaestro. It is the best fit here if you care about summaries, replies, and Outlook-specific email handling more than general writing help. [ 11 , 12 ]
- You mainly want better wording everywhere: Grammarly. Pick it when tone, clarity, and rewrites matter more than inbox triage, and keep the Office add-in retirement in mind. [ 13 , 15 ]
- You run a shared Outlook mailbox like a team queue: Hiver. It is the strongest option here when you need ownership, SLAs, notes, analytics, and AI help in one place. [ 16 , 17 , 18 ]
- You want the most assistant-like experience: Fyxer. It is the better pick if you want proactive sorting, voice-matched drafts, and meeting follow-through, not just a smarter compose box. [ 19 , 20 ]
FAQ about Outlook AI and Copilot
What is the best AI email assistant for Outlook?
There is no single best option for everyone. Copilot in Outlook is usually the first place to look if you already use Microsoft 365. After that, the right pick depends on the job: MailMaestro for an Outlook-first add-in, Grammarly for writing help, Hiver for shared inboxes, and Fyxer for a more proactive assistant style.
Does Outlook have a built-in AI email assistant?
Do I need the Microsoft Copilot add-on to use AI in Outlook at work?
Can Copilot in Outlook work with Gmail or other email accounts added to Outlook?
In supported Outlook apps, yes. If you sign in with an eligible Copilot account, Copilot features can be available across connected accounts on the same device.
Sources [ 7 ]
What is the biggest current limitation with Outlook Copilot?
Which option is best for Outlook shared mailboxes?
Is Grammarly enough as an Outlook AI assistant?
Can these tools send emails automatically for me?
What should my team check before rollout?
Want a different email setup while you compare Outlook AI?
Mailbird is an email client, not an Outlook AI add-in. If you want a different email setup while you compare these tools, try Mailbird .
Sources
- Microsoft Tech Community — Copilot in Outlook: New agentic experiences for email and calendar
- Microsoft Support — How Copilot Chat works in Microsoft 365 apps
- Microsoft Support — Frequently asked questions about Copilot in Outlook
- Microsoft Support — What Copilot license do I have
- Microsoft — Microsoft 365 Copilot plans and pricing for business
- Microsoft — Microsoft 365 Copilot plans for individuals
- Microsoft Support — Sharing Copilot in Outlook
- Microsoft Support — AI credits and limits for Microsoft 365 subscriptions
- Microsoft Learn — Release notes for Outlook for Windows (new)
- Microsoft Support — Shared and Delegated Mailboxes with Microsoft Copilot Chat in Outlook
- Microsoft Marketplace — AI MailMaestro for Outlook
- MailMaestro — Pricing
- Grammarly — Pro plan
- Grammarly Support — Grammarly’s product offerings
- Grammarly Support — Grammarly for Microsoft Office will be discontinued soon
- Hiver — Outlook Shared Mailbox for Teams
- Hiver — Hiver Omni pricing
- Hiver — AI Copilot for customer support
- Fyxer — AI Email Assistant for Gmail & Outlook
- Fyxer — homepage and pricing overview
