Best Email Client for Windows in 2026: 8 Picks Compared

The best email client for Windows in 2026 depends on your need. For AI triage and drafting across mixed accounts, our top pick is AI Emaily, which we build. Thunderbird is the best free option, the new Outlook fits Microsoft 365, and eM Client is the softest landing from classic Outlook.

This guide compares eight email clients that run on Windows 10 and 11: native installers, desktop apps built on web technology, and single-service apps. AI Emaily comes first as our top pick for that job, and every entry, ours included, says who should skip it. If you also use a Mac or Linux, our guide to the best desktop email clients compares across systems.

The best Windows email client for most people#

Start with the line that sounds like you. Each one is a quick pick, and the details are further down.

• Best for AI triage and drafting: AI Emaily. In Copilot mode the AI drafts and you approve every send, with undo and an audit trail. We build it, so verify the trial terms yourself.
• Best free email client for Windows: Thunderbird. No cost, no lock-in, and no AI you did not ask for. For more options see our best free email client guide.
• Best mail app for Windows if you live in Microsoft 365: the new Outlook, already on new Windows 11 PCs.
• Best mail client for Windows if you are leaving classic Outlook: eM Client, a familiar desktop app with calendar and tasks.
• Best email app for one inbox across several accounts: Mailbird.
• Best for a polished cross-platform inbox with light teamwork: Spark.
• Best for private, encrypted mail: Proton Mail (one encrypted service) or Canary Mail (encryption over your existing accounts).
• Still on an older PC: see our best email client for Windows 10 guide.

The 8 best Windows email clients at a glance#

AI Emaily leads as our pick for AI triage and drafting across mixed accounts. The other rows run from the widest fit for a Windows PC to the most specialised. Free option is the column to check first, because no two clients here handle it the same way.

Replacing the Windows Mail app#

If you landed here because the built-in app stopped working, that is expected. Microsoft ended support for Windows Mail and Calendar on 31 December 2024, and they can no longer send or receive mail. New Windows 11 PCs ship with the new Outlook as the default mail app, which is a very different program from the classic Outlook many people still run.

Local mail stored in the old app stays exportable. Our guide on what replaced the Windows Mail app walks through that, and any client below can take over from there.

How we compared them#

We did not score these apps with a stopwatch. We compared documented capabilities from each vendor's own pages, and where a vendor does not publish something, we say so. Here is what we weighed:

• Provider coverage: does it connect Gmail, Outlook or Microsoft 365 and plain IMAP, or only one service?
• AI that acts: does it just autocomplete, or can it triage, draft and follow up, with your approval before anything sends?
• Control and trust: undo, an audit trail of what the app did, and a clear stance on training AI on your mail.
• Windows fit: a real installer with taskbar presence and notifications, and support for Windows 10 and 11.
• Packaging shape: free tier, trial, one-off licence or subscription. We describe the shape, not the price, because prices move.

The 8 clients in detail#

Each entry covers what the client is, how it ships on Windows, and who should skip it. The order matches the table.

1. AI Emaily: best for hands-off triage and drafting#

AI Emaily is an AI-native email client, and we build it, so weigh this entry against the independent ones. On Windows 10 and 11 it installs from an x64 setup file, with the current version on our download page, and runs as a desktop app with its own window, taskbar entry and system notifications.

Drafts start from the Personal Context you set and per-client profiles. Manual keeps AI on demand, and in Copilot the AI drafts while you approve every send. Autopilot, on the Autopilot and Team plans, handles routine mail within your rules. Compose has a 10-second undo window, Autopilot sends wait out a 5-minute countdown, and agent actions go into an audit trail. Your mail is not used to train models.

It connects Gmail, Outlook and Microsoft 365, plus iCloud, Yahoo, Fastmail and other IMAP accounts in one inbox. That is useful on Windows, where many people juggle a work Microsoft account and a personal Gmail.

• Best for: people with several accounts who want triage and drafting handled, with approval on every send in Copilot.
• Skip it if: you need offline mail, shared mailboxes or send-as on Microsoft 365, a free plan, or a Linux app. The Windows app is an Electron shell around the web app, so it will not match a native binary on memory or OS integration.
• Packaging: no free plan. 7-day free trial on Pro or Autopilot, then paid, with a 14-day money-back guarantee. See pricing.

2. Mozilla Thunderbird: best free, open-source client#

Thunderbird is the default recommendation for anyone who wants a capable client that costs nothing and answers to no one. It is free and open source, funded by donations, and it connects Gmail, Outlook and any IMAP account. You get multiple accounts, a unified inbox and a deep add-on ecosystem, and a separate legacy build stays available for Windows 7 and 8.1.

Thunderbird says plainly that it does not secretly train AI on your private conversations. The 153 release in July 2026 added built-in Exchange support through Exchange Web Services. Microsoft began disabling that protocol in Exchange Online in October 2026, so on Microsoft 365, ask your admin before you rely on it.

• Best for: anyone who wants free, independent mail with local storage.
• Skip it if: you want AI that acts. There is no built-in agent, and it asks more of you to set up than a polished commercial client.
• Packaging: free forever, with optional donations.

3. New Outlook: best if you live in Microsoft 365#

The new Outlook is the default mail app on new Windows 11 PCs and is free to use. It connects Outlook and Gmail accounts, and Microsoft lists IMAP and POP as available. Copilot depends on your plan: Microsoft 365 Personal, Family and Premium use monthly AI credits, and work accounts use a paid add-on.

The catch is feature parity. Microsoft lists COM add-ins, VBA macros, custom forms and voting buttons as not supported in the new Outlook, while offline support and PST files are only partly available. Any workflow built on those stops working the day you switch.

Classic Outlook is not going away tomorrow. Microsoft says existing installs are supported until at least 2029. Its public model has three stages, opt-in, opt-out and cutover, with at least 12 months' notice to IT admins before opt-out and before cutover.

• Best for: Microsoft 365 users who want everything in one Microsoft app.
• Skip it if: you rely on classic add-ins, macros or voting buttons.
• Packaging: free app; Copilot access varies by plan. Check Microsoft's plan page for your account type.

4. eM Client: best for classic-Outlook refugees#

eM Client is the closest thing to a modern, supported replacement for classic Outlook on Windows. It is a native app with mail, calendar, contacts, tasks and chat in one place, plus S/MIME and PGP encryption. If you are leaving classic Outlook because of the new-Outlook changes, this is the softest landing.

It connects Gmail, Microsoft 365, Exchange and IMAP accounts, and eM Client says it can import from Outlook and Thunderbird, which matters when you are moving years of mail. It also has built-in translation and an AI Add-on for assistance and summaries. These are helpers, not an autonomous agent.

• Best for: people who want a full desktop client and like managing mail by hand.
• Skip it if: you need the free version for work, because it covers home use only.
• Packaging: free for home use on 1 device with 2 accounts. Paid Personal and Business licences come as a yearly subscription or a one-time payment, and the AI Add-on comes with the yearly plans.

5. Mailbird: best unified inbox with app integrations#

Mailbird was built for Windows first and has been a popular Windows email client for years. Its pitch is one unified inbox for Gmail, Outlook and IMAP accounts, and it now runs on Mac as well under one licence. Mailbird's site also lists iPhone and Android apps, while one of its own comparisons calls them beta, so check the app stores.

Its AI is opt-in. Mailbird describes a local connection that lets outside assistants such as Claude or ChatGPT read mail and draft replies, with a separate confirmation for each send, and it lists a built-in assistant as a closed beta. Check its support pages for the current setup.

• Best for: one tidy inbox across several accounts in a Windows-first app.
• Skip it if: you want a built-in AI agent today, or need POP on a Mac.
• Packaging: Mailbird's site describes a free plan for one account, a 7-day Premium trial, and paid Premium as a subscription or a one-time payment. It has shifted before, so check the current plans.

6. Spark: best for design and light team features#

Spark, from Readdle, is a design-forward client for 64-bit Windows 10 or later, and you can get it from its site or the Microsoft Store. Its Smart Inbox groups and prioritizes mail, and it connects Gmail, Outlook and IMAP accounts on Windows, Mac, iPhone and Android, so your setup follows you from a PC to a phone.

For small teams, paid plans add shared drafts, comments on emails and delegation, which most desktop clients skip. Spark's AI compose and summaries assist with writing and reading rather than running your inbox on its own.

• Best for: small teams and anyone who values design across devices.
• Skip it if: you want AI on the free tier, which only gets a limited preview.
• Packaging: free tier, plus paid Plus, Pro and Enterprise plans. Confirm the split on Spark's pricing page.

7. Canary Mail: best for encryption-first users#

Canary Mail leads with privacy, which makes it a common pick for people who want more control over who sees their mail. It runs on Windows, macOS, iOS and Android, and connects Gmail, Outlook and IMAP accounts.

Check the tier before you decide, because the headline features are not all free. Canary's pricing page puts PGP encryption on Pro+, and its AI Copilot on Growth and Pro+. The AI assists you rather than acting on its own.

• Best for: people who put private, encrypted mail ahead of an AI that runs the inbox.
• Skip it if: you expect PGP or AI on the free plan.
• Packaging: free tier, plus paid yearly or lifetime plans.

8. Proton Mail: best for end-to-end encrypted mail#

Proton Mail is different from the others here: it is a client for one service, not a universal inbox. The Windows desktop app gives you your Proton mailbox in a real desktop window, and it needs Windows 10 or later.

The security model is the draw. Proton uses end-to-end and zero-access encryption, so Proton cannot read the contents of your mail. That is a different guarantee from a client that simply displays a Gmail account.

Proton accounts do not connect to AI Emaily at all, so it cannot serve this reader. If you want Proton mail in another desktop client such as Thunderbird, Proton Mail Bridge does that on a paid plan.

• Best for: people for whom private, encrypted email is the whole point.
• Skip it if: you need one app across many providers.
• Packaging: a free Proton account gets a 14-day desktop app trial; after that the app needs a paid plan.

Be honest about where each loses#

If you rely on classic Outlook add-ins, such as a CRM plug-in, VBA macros or voting buttons, none of these clients restore them, and the new Outlook drops them too. You may need to keep classic Outlook, supported until at least 2029, for that one workflow.

AI Emaily loses on three counts we should state. It does not work offline: no mail is cached on your device and replies are not queued, though scheduled sends and agent work continue on the server. It has no shared mailboxes or send-as on Microsoft 365. And the Windows app is a shell around the web app, so it will not match a hand-built native binary on memory.

If you live entirely inside Microsoft 365 and never touch another provider, the new Outlook you already have may be enough. The case for switching gets stronger the more accounts and manual triage you juggle.