Best Email Client for Exchange on Linux

On Linux, the best email client for Exchange depends on whether your mailbox is on Exchange Online or on Exchange Server in your own building. For Exchange Online, GNOME Evolution with the evolution-ews backend is the most complete desktop option today, and it is also the one on a clock: Microsoft began blocking Exchange Web Services by default on October 1, 2026 and shuts it down entirely on April 1, 2027. For on premises Exchange Server, nothing changes and Evolution stays fine. For a personal Outlook.com address, or for an Outlook mailbox you read alongside Gmail and your own domain, IMAP with OAuth 2.0 is the route that outlives the deadline, because Microsoft is retiring basic authentication rather than IMAP itself.

That is the whole answer, and it is worth stating up front because almost every roundup of Linux mail clients written before 2026 gives advice that expires this autumn. The lists are not wrong about which clients are good. They are silent about the fact that the connector holding most of them to Microsoft is being switched off.

The deadline that changes the recommendation

Exchange Web Services is the protocol a non Microsoft client uses to talk to an Exchange mailbox with full fidelity, meaning mail plus calendar plus contacts plus free/busy. On Linux it is the only such connector that ships in a mainstream desktop client. Microsoft has been signalling its retirement for years and has now put hard dates on it.

Microsoft's replacement is Microsoft Graph, paired with the Exchange Online Admin API. Graph is a good API. The problem for Linux users is not the API, it is that somebody has to write a Graph backend for the client you use, and on the Linux desktop that work has not landed. The GNOME project has not shipped a Graph backend for Evolution. eM Client users have been asking for Graph support on the vendor forum rather than being handed a release note about it, and eM Client has no Linux build anyway.

I want to be careful here rather than dramatic. This is not a prediction that Evolution stops opening on a particular Tuesday. Tenants can defer, administrators can use the allow list, and a Graph backend could appear. It is a reason to find out which side of the line you are on now, while there is time to move deliberately instead of on the morning mail stops arriving. A vendor deadline with a fixed date and a named owner is exactly the sort of item that belongs in whatever system your team uses to track obligations against their due dates, rather than in one administrator's memory.

What is the best email client for Exchange on Linux?

GNOME Evolution, for a managed Exchange mailbox, today. It is the default mail client on GNOME, which means it is already installed on Fedora Workstation, on RHEL and on stock Ubuntu GNOME sessions. The evolution-ews package connects a Microsoft 365 account with its calendar and address book, and it has supported OAuth 2.0 since version 3.27.91, so modern authentication is not a blocker. Nothing else on Linux offers that depth against Exchange.

The caveat is the one above. Evolution reaches Exchange Online over EWS, so its Exchange support inherits the October 2026 date. If your mailbox lives on Exchange Server in a rack you can walk to, ignore all of this and use Evolution happily.

Can Thunderbird connect to Exchange?

Over IMAP, yes, and that route is not affected by the EWS retirement. Thunderbird 153 ships native 64 bit and 32 bit Linux builds as a deb from the Mozilla Team PPA, as the snap Ubuntu preinstalls since 24.04, and as the official Flatpak on Flathub. It authenticates to Exchange Online with modern authentication and it merges several accounts into real Unified Folders, which is the feature most people are actually after.

What Thunderbird does not do natively is Exchange calendar and contacts. There is no EWS backend in the shipping product and no Graph backend either. Historically that gap was filled by a paid third party add-on. So if your requirement is mail only, Thunderbird over IMAP is the most durable desktop answer on Linux in 2026. If your requirement includes the shared calendar your colleagues book you into, it is not.

Is IMAP being retired for Microsoft 365?

No, and this is the single most misread part of the story. Microsoft is retiring basic authentication, which is a way of presenting credentials, not the IMAP protocol. IMAP, POP and SMTP continue to be supported against Exchange Online and Outlook.com when the client authenticates with OAuth 2.0, and Microsoft publishes documentation on doing exactly that. The retirement notices that mention IMAP are about the password format, not the protocol.

For Linux that distinction decides the recommendation. The protocol with the clearest future on this platform is the oldest and plainest one. Anything built on IMAP in 2026 is the least likely to need rebuilding in 2027.

Is there an Exchange client for Linux?

Yes, and there are three kinds, which is where most of the confusion comes from. A native Linux Exchange client is one that speaks Exchange itself, and on the desktop that means Evolution with evolution-ews: mail, calendar, contacts and free/busy, all in one window. A Linux Exchange mail client is anything that reads the same mailbox over IMAP, such as Thunderbird, KMail or Geary, which gets you mail and nothing else. The third kind is Microsoft's own web client installed as an app, which is complete but shows one mailbox.

Which one you want depends on a single question: does the calendar your colleagues book you into have to live in the same program as your mail? If yes, the only real Exchange client for Linux is Evolution, with the deadline described above. If mail is enough, every IMAP client on the platform qualifies and none of them is affected by the EWS change.

Which Linux email client for Office 365 still works after October 2026?

For mail alone, any IMAP client that signs in with modern authentication, and Thunderbird is the strongest of them. For mail plus the shared calendar, Evolution, as long as your tenant keeps it on the EWS allow list until the final shutdown on April 1, 2027. That is the whole short list of a Linux email client for Office 365 today, which is why every exchange client linux thread ends up naming the same two programs.

The searches vary far more than the answer does. Whether you typed linux mail client exchange, linux exchange email client, exchange linux client or exchange mail linux, you want the same thing: a Microsoft mailbox open on a Linux desktop. Sort it by what you cannot afford to lose. If losing the calendar in October would stop your week, test Evolution against your tenant now and ask your administrator whether it is on the allow list. If mail is what matters, move that account to IMAP now and the deadline stops being your problem.

One search in this family is a different question entirely. Exchange for Linux in the sense of running Exchange Server itself on a Linux machine does not exist: Exchange Server installs only on Windows Server. On Linux the equivalent job is done by an IMAP server such as Dovecot with Postfix for sending, and every client in the table below reads that without any of the EWS complications.

Linux Exchange clients compared side by side

How do I set up Exchange email on Ubuntu?

Install Evolution and the EWS backend, then let autodiscover do the work. On Ubuntu that is sudo apt install evolution evolution-ews, after which you add an account, choose Exchange Web Services as the type, enter your address, and use the Fetch URL button so Evolution finds the server settings itself. Sign in through the browser prompt when it appears, because that is the OAuth 2.0 step and typing a password into the old field will fail.

That makes Evolution the Ubuntu Exchange client most people end up with, and for a good reason: it is the only one in the Ubuntu archive that talks to Exchange natively rather than through IMAP.

If your organization blocks EWS already, or you only need mail, add the account as IMAP instead using outlook.office365.com on port 993 with SSL, and SMTP on port 587 with TLS. A managed tenant will require OAuth for that too, so the client has to support modern authentication rather than an app password.

Can I use Outlook on Linux instead?

Only in a browser. Microsoft has never shipped a native Outlook desktop build for any Linux distribution and has announced no plans to, so the supported route is Outlook on the web installed as an app from the Chrome or Edge menu. That gives you a standalone window, a launcher entry and offline reading once you enable it. It handles one mailbox properly and it is entirely unaffected by the EWS retirement, because it is Microsoft's own client talking to Microsoft's own service. The full picture, including the community Snap wrappers and why they are not what they look like, is on our page about Outlook for Linux and the Outlook app on Ubuntu.

Which client should you actually pick?

Sort yourself into one of four situations and the choice makes itself.

One managed Microsoft 365 mailbox, and you want calendar and contacts on the desktop. Evolution today, and a conversation with whoever administers your tenant about the EWS allow list before October. If that conversation goes badly, Outlook on the web installed as an app is the fallback that definitely survives, and it costs nothing extra because you already pay for the account.

One managed mailbox, mail only. Thunderbird over IMAP with modern authentication. It is unaffected by the deadline, it is packaged for every distribution, and it will still be there in 2028.

On premises Exchange Server. Evolution, and stop worrying. Microsoft has been explicit that the retirement applies to Microsoft 365 and Exchange Online only and that nothing changes for Exchange Server.

An Outlook.com or Hotmail address that is one of several you read. This is the case none of the Exchange advice covers, because it is not really an Exchange problem. If your morning is a personal Outlook address plus a Gmail account plus something on your own domain, the client that fits is one that treats all of them as equals rather than treating one as the primary. Thunderbird with a Microsoft sign in holds all three; Inboxes holds the Gmail and domain mailboxes and takes the Outlook address by forwarding, because it cannot sign in to Outlook.com. The wider comparison of desktop options is in our guide to picking an email client for Linux.

What about Wine, or an Electron wrapper?

Running desktop Outlook under Wine or Bottles is unreliable and unsupported by both Microsoft and the Wine project, and the versions that half work tend to break at the next Outlook update. The Snap Store listings that promise Outlook for Linux are Electron shells around Outlook on the web. They run, they are not Microsoft software, they trail the web version, and they show the same single mailbox the browser shows. If a dedicated window was the goal, installing the web app from the browser menu gets you the same window with nothing extra to maintain.

The one honest heavyweight route is a Windows virtual machine running real Outlook. It works completely, it is the only way to get the actual program, and it costs you a Windows license, several gigabytes of RAM and a second operating system to patch. For a small number of people whose job depends on a specific Outlook add-in, that trade is correct. For everyone else it is a lot of machinery to avoid learning a different mail client.

The short version

Evolution is the best Exchange client on Linux and it is the one with a deadline. Thunderbird is the most durable, because IMAP is not being retired. Outlook on the web is the option Microsoft actually supports on this platform and it is better than its reputation. And if the real problem is that an Outlook address is one of four you check every morning, the Exchange question was never the right question, because no Exchange client is going to show you the other three.

That last case is worth separating out, because it is the one people most often misdiagnose. If the Exchange mailbox is a work account you check in Outlook on the web anyway, and the mail that actually piles up is a Gmail address, an old ISP address and something at your own domain, then no amount of Exchange tuning touches the problem. Those three all speak IMAP, and an IMAP client can hold every one of them on a single board on a Linux desktop, in a browser, with the source account marked on each message. To be clear about the boundary: a managed Microsoft 365 mailbox will not join it, because Microsoft has retired basic authentication for Exchange Online. Keep Outlook on the web open for work, and stop keeping three other tabs open for everything else.