AI Email Clients That Work With Both Gmail and Outlook

Most "best AI email client" roundups quietly assume one thing: you live in Gmail, or you live in Outlook, and you want an AI layer over that one account. That is not the reader who searches for a cross-provider client. If you have a Gmail address for personal mail and a Microsoft 365 address for work — or a Google Workspace domain plus an Outlook.com side project, or three of each — the whole point is that one AI inbox has to reach into both worlds and keep the differences straight.

That is a smaller field than the general "AI email" market makes it look. Plenty of AI writing tools sit on top of one provider. Fewer are real email clients that authenticate cleanly against both Google and Microsoft, respect Gmail labels and Outlook folders as different things, and let the AI do the same job in both. This post is only about the ones that do.

One disclosure up front: we build AI Emaily, which is one of the clients on this list. It is entry number one because it is our site and because native cross-provider AI is what we ship, but the table below concedes where other tools do things we do not. If a competitor genuinely fits your situation better, we will name them and tell you why.

The short answer#

For most professionals who split their day between a Gmail account and a Microsoft Outlook account and want one AI running across both, AI Emaily is the pick. It authenticates natively against Google (OAuth) and Microsoft (OAuth), presents both accounts in one unified inbox, and applies the same triage, drafting and follow-up agent across Gmail labels and Outlook folders — with approve-before-send by default and an audit trail on every action.

If you specifically do not want to leave the Gmail and Outlook web interfaces you already use, Fyxer is the honest alternative. It is a browser overlay, not a client — it adds AI on top of the mail apps you already open, on both providers. That is a real advantage for readers whose muscle memory is already burned into Gmail and Outlook, and we are not going to pretend otherwise.

If your workload is a shared team inbox rather than a personal one, Missive handles the shared-inbox collaboration case more maturely than we do today. And if speed and a specific keyboard workflow are your religion, Superhuman Mail (now part of the Superhuman Suite after Grammarly's 2025 acquisition) is what to look at.

How we compared these#

The axis that matters for a Gmail-plus-Outlook reader is not the AI feature list. It is the architecture, because architecture decides what the AI can and cannot do on each provider. There are three shapes.

The first is the native OAuth client. You install (or open) a new mail app, authorize both Google and Microsoft through their real OAuth flows, and the app becomes your inbox. Because the connection is native, Gmail labels stay labels, Outlook folders stay folders, and the client can act — file, send, snooze, run rules — through each provider's API rather than screen-scraping a web page. This is the shape AI Emaily, Shortwave, Superhuman Mail, Spark, and Canary Mail all take. The trade is that you leave the Gmail and Outlook UI behind.

The second is the overlay. A browser extension injects AI into gmail.com and outlook.office.com without replacing them. You keep every native UI habit, and you gain drafts, triage suggestions, and meeting notes on top. Fyxer is the clearest example. The trade is that the AI is bounded by what an extension can see and do — it can suggest labels, but it cannot rebuild the way threading, prioritisation or a unified inbox work, because someone else's app owns that.

The third is bridged IMAP. Any generic IMAP/SMTP client can log into Gmail and Outlook, and some AI clients still rely on this rather than provider APIs. It is worth flagging that both Google and Microsoft support IMAP for third-party clients, per their own documentation, but that support has real limits — Gmail's IMAP maps labels to folders in a lossy way, and Microsoft's Exchange Online IMAP does not expose the same categories, rules, or focused-inbox behaviour that the Graph API does. A client that only speaks IMAP will feel thinner on both providers than a native OAuth one.

The other things we scored — approve-before-send, undo, audit trail, whether the AI trains on your mail, packaging shape — matter, but they matter downstream of that architecture choice. A client that cannot act on the API cannot offer meaningful autonomy in the first place.

Comparison: AI email clients across Gmail and Outlook#

The table below covers the seven we consider real cross-provider candidates as of August 2026. Packaging shapes are stated in shape — free tier, trial, per-seat, usage-metered — rather than in dollar figures, because vendor pricing pages move faster than a blog post can. Check current pricing on each vendor's page before you buy.

Everything below unpacks those rows in turn. AI Emaily gets the most space because we know it best and it is what we sell; the others get roughly the same treatment on the axes a cross-provider reader actually cares about.

1. AI Emaily — the pick, and why#

AI Emaily is a native AI email client that authenticates through Google OAuth for Gmail and Google Workspace, and through Microsoft OAuth for Outlook.com, Hotmail, and Microsoft 365 tenants. It is not an overlay and it is not IMAP-bridged for those two providers — it uses the Gmail API and Microsoft Graph, which is what lets Gmail labels stay labels, Outlook folders stay folders, and the same agent act cleanly on both sides.

The AI is a chief-of-staff-style agent with three autonomy modes: Manual (it suggests, you do everything), Copilot (it prepares the reply, filing or schedule and waits for your one-click approval), and Autopilot (it handles the routine work you have defined on its own). Every mode carries approve-before-send by default, undo, and a full audit trail of what the agent touched. Draft voice comes from a user-set Personal Context brain and per-client profiles you edit — not from a passive model that quietly ingests your sent mail.

Coverage extends past Gmail and Outlook: iCloud, Fastmail, Proton, Yahoo, and generic IMAP accounts land in the same unified inbox, which matters if a Gmail-plus-Outlook shopper is really a three-or-four-account shopper. On desktop, we ship a downloadable app for macOS (Apple Silicon only — no Intel Mac build) and a Windows installer. On mobile there is a native iOS/iPadOS app; Android is a PWA today, with a native Android app on the roadmap. There is no Linux build.

Packaging is a 7-day free trial on Pro or Autopilot (card required, $0 if you cancel before day seven), followed by paid plans. Check the current shape at aiemaily.com/pricing before you sign up. We build AI Emaily — that is why it leads this list — and it is also why it earns the top slot: cross-provider native OAuth with an agent that can actually act on both providers is the specific job of this post.

2. Fyxer — the overlay that keeps your existing UI#

Fyxer is the overlay to look at if the whole appeal of a cross-provider AI is that you do not have to leave Gmail or Outlook. It installs as a browser extension and layers drafts, triage suggestions, and meeting-note follow-ups into the mail UIs you already have open on both providers.

This is a real dimension where Fyxer beats us: your muscle memory, keyboard shortcuts, filters, add-ins, and every Gmail-or-Outlook quirk you have already internalised keep working, because you are still in the native app. A native client (AI Emaily included) asks you to leave that behind. For a reader who has spent five years in Outlook and is not going to change, an overlay is honest fit.

The trade is architectural: an extension is bounded by what the host app lets it see and do. The overlay can suggest a draft, but it cannot rebuild a unified inbox across your Gmail and Outlook, and its "autonomy" is closer to prepared-drafts than to an agent that acts through the API. Packaging is trial-plus-paid; verify current shape on fyxer.com before you buy.

3. Superhuman Mail — the fast client, now part of the Suite#

The name is now ambiguous and worth disambiguating: Grammarly acquired Superhuman (the email client) in July 2025 and renamed the parent company to Superhuman in October 2025. What used to be simply "Superhuman" is now Superhuman Mail (the client) inside the Superhuman Suite (the Grammarly-plus-tools bundle). Reviews written before mid-2025 are describing the earlier packaging.

The product itself is the same lineage: a keyboard-first native client with AI drafting, triage assists, and a legendary speed reputation. It supports Gmail and (added after the earlier Gmail-only era) Microsoft Outlook natively. If keyboard speed and a specific inbox aesthetic are what you are optimising for, this is the honest recommendation over ours — we do not compete on being the fastest keyboard workflow on the market.

Packaging is paid tiers only, sold under the new Superhuman Suite branding; verify current shape on superhuman.com. The onboarding trade is that Superhuman is a client you switch into fully — you leave the Gmail and Outlook UIs behind, same as us.

4. Shortwave — the AI-first Gmail client, with Outlook now#

Shortwave was built by ex-Google engineers who worked on the original Inbox by Gmail, and for most of its life it was a Gmail-only AI client with strong semantic search and thread summaries. That Gmail origin is a real advantage on the Google side — Shortwave has invested harder in Gmail archive search and semantic recall than we have, and if your workload is 90% Gmail with a light Outlook account, that difference is felt.

For a cross-provider reader, the question is Outlook support. Shortwave has announced and shipped work in this direction; verify the current state on shortwave.com/pricing and their release notes before you rely on it, because "native across both" for a Gmail-origin client can lag the marketing by a version or two.

Packaging is a free tier plus paid tiers. As with every vendor in this list, the actual numbers move — check the pricing page.

5. Spark — the multi-provider client that added AI#

Spark by Readdle is one of the older cross-provider clients on this list. It has supported Gmail, Outlook, iCloud, Yahoo, IMAP, and Exchange natively for years, and it added an AI layer ("Spark AI") for drafting and summarisation. If your priority is stable multi-account handling and you want AI as a helpful addition rather than the reason the client exists, Spark is the mature option.

Where it differs from AI Emaily: Spark's AI is oriented around writing and reading help, not around a persistent agent that triages, chases follow-ups, and acts on your behalf with approve-before-send and an audit trail. Both are valid designs — the question is whether you want an AI-native client or a well-established client with AI added.

Packaging is a free tier plus a Premium subscription; verify current tiers on sparkmailapp.com.

6. Canary Mail — encrypted, cross-provider, AI-first#

Canary Mail supports Gmail (OAuth), Outlook and Microsoft 365 (Exchange/OAuth), iCloud, Yahoo, and generic IMAP natively, and it has leaned into AI features around drafting, sender scoring, and summaries. Its distinguishing pitch has been end-to-end encryption (PGP support) and an emphasis on privacy alongside the AI.

For a Gmail-plus-Outlook reader, Canary is a plausible cross-provider pick, particularly if PGP matters to you. The tradeoffs versus AI Emaily are on the agentic layer — Canary's AI is closer to feature-set (draft, summarise, sender-score) than to a modes-with-audit agent that acts on both mailboxes.

Packaging is a free tier plus paid tiers (Growth, Pro+ etc.); verify current shape on canarymail.io.

7. Missive — the shared-inbox case#

Missive is not a personal email client with an AI layer on the side — it is a shared-inbox collaboration platform that happens to authenticate natively against Gmail and Outlook and now includes AI features for drafting and summarisation. If the real reason you want cross-provider AI is that your team handles support@ and sales@ on Google Workspace while your executive assistants handle a Microsoft 365 tenant, Missive is where to look.

This is the concession we owe: Missive's shared-inbox collaboration — assignment, side-conversations, teamwide review flows — is more mature today than what we ship. For a personal cross-provider inbox we would still argue for AI Emaily's agent model over Missive's collaboration model, but if collaboration is the job, ranking ourselves above Missive would be a category error.

Packaging is a free tier plus per-seat paid plans, sold to teams; verify current shape on missiveapp.com/pricing.

How to choose for your situation#

The five real forks in this decision, mapped to the row that wins each:

1. 1

   Personal Gmail + work Outlook, and you want an AI agent that acts

   AI Emaily. Native OAuth on both, one unified inbox, an agent that triages, drafts and follows up with approve-before-send by default. This is the case we are built for and the one to start a trial on.

2. 2

   You refuse to leave the Gmail and Outlook web UIs

   Fyxer. It is an overlay by design; it will not rebuild your inbox, and that is the point. You keep every native habit and get AI drafts and triage on top. Trade the agent depth for zero UI change.

3. 3

   Speed and a keyboard-first workflow above all else

   Superhuman Mail. Now under the Superhuman Suite / Grammarly umbrella, but the client itself is the same lineage — the fastest keyboard experience in this list, cross-provider on Gmail and Outlook.

4. 4

   Gmail-heavy with a light Outlook account, and archive search matters

   Shortwave, once you have verified its Outlook coverage against your specific tenant. Its Gmail-side semantic search is a real strength we do not out-compete on.

5. 5

   Shared team inbox across Google and Microsoft

   Missive. Shared-inbox collaboration is its native shape; assignment, side-conversations, and review flows are built in. Add AI as a bonus rather than the reason.

6. 6

   You want native multi-provider with AI as an addition, not the point

   Spark or Canary Mail. Both have supported Gmail and Outlook natively for years and added AI over time. Canary leans further on privacy (PGP); Spark leans on polished mainstream UX.