Pick by what you actually use
Outlook Alternative: Best Alternatives and Substitutes for Microsoft Outlook
Most people searching this are not looking for a better program. They are looking for a way out of one that keeps changing under them. Here is the honest field, including the two places we are the wrong answer.
Any OS · No installer · Up to 120 mailboxes
The short answer
There is no single best Outlook alternative, because Outlook is four products in one box. If you are replacing the calendar and contacts as well as the mail, the answer is Thunderbird, which charges no license fee, or eM Client, which sells a pay once license at 59.95 dollars in the US and keeps the classic Outlook layout almost intact. If you are replacing Outlook on a phone or across a Mac and a PC, the answer is Spark. If what you are really replacing is the experience of opening five separate mailboxes every morning, none of those solve it, because merging accounts and sorting them are different features. Inboxes is the last kind: a browser board that connects every IMAP mailbox and tags each message with a category and a spam verdict before you read it. One hard limit first, because it disqualifies us for a lot of readers: a managed Microsoft 365 work mailbox will not connect to us.
Last updated August 2026
Why this search spiked
Three reasons people go looking for an Outlook substitute
Knowing which of these is yours narrows the field faster than any feature table, because the three have completely different answers.
The program is being replaced and you did not ask for it. Microsoft is moving Windows users from classic Outlook to new Outlook in three stages. Today it is opt in: the Try the new Outlook toggle appears and you can switch back. Next comes opt out, where new Outlook is on by default. Then cutover, where switching back stops being an option. Microsoft commits to at least twelve months of notice before each of the last two stages hits production, and says existing classic Outlook installations under perpetual and subscription licensing stay supported until at least 2029. So there is time, but the direction is fixed, and new Outlook is a different program: no COM add ins, no POP3, limited public folders, no manual IMAP and SMTP server settings exposed, and offline working that people still complain about.
You are paying for a suite to use one part of it. Microsoft 365 Personal is $9.99 a month or $99.99 a year, Family is $12.99 or $129.99, and Premium is $19.99 or $199.99. If Word and Excel sit unopened and you subscribed for the mail client, the math gets uncomfortable. Worth knowing before you cancel anything: both new Outlook for Windows and Outlook for Mac now work without a subscription. You get ads in the message list instead. For a lot of people that alone settles the question.
One program, and you have six mailboxes. This is the reason that no other client on this page fixes, and it is the reason we exist. Outlook connects multiple accounts and so does almost everything else here, but connecting is not sorting. Six inboxes merged into one view is one longer inbox, and you still read every line to work out which of them matters. That is a different problem from which desktop program you run.
The field, compared
Outlook alternatives and replacements, side by side
Pricing taken from each vendor public pricing page and re-checked in August 2026. Most of this table costs less than we do, and for many readers one of these rows is the right answer.
Swipe to see all columns →
| Client | Best for | Runs on | Calendar and contacts | Price |
|---|---|---|---|---|
| Inboxes | Many mailboxes sorted automatically, on any machine | Any browser, so any OS | No, mail only | $29 a month flat |
| Thunderbird | The closest thing to a like for like replacement | Windows, Mac, Linux, Android | Yes, both built in | No license fee, open source |
| eM Client | Keeping the classic Outlook layout and workflow | Windows, Mac | Yes, plus tasks and notes | 29.95 EUR a year, or 39.95 EUR once |
| Mailbird | Chat and calendar panes docked beside the mail | Windows, Mac | Calendar yes, via connected apps | 4.03 EUR per user monthly yearly, or 99.75 EUR once |
| Spark | The same accounts on a phone, a Mac and a PC | Mac, Windows, iOS, Android | Calendar yes, contacts limited | 10 EUR per user monthly, or 120 EUR a year |
| Canary Mail | Encrypted mail with PGP built in | Mac, Windows, iOS, Android | Calendar on paid tiers | $36 a year, or $100 a year for Pro+ |
| Apple Mail | A Mac owner who wants nothing else installed | macOS, iOS only | Yes, as separate Apple apps | Included with macOS |
| New Outlook | Staying with Microsoft on a modern build | Windows, Mac, browser | Yes, the full Microsoft stack | Preinstalled, ads without Microsoft 365 |
| Classic Outlook | COM add ins, public folders, a full offline store | Windows | Yes, the most complete of any client here | Microsoft 365, supported to at least 2029 |
The column that decides most of these is the third one, not the price. Outlook has never shipped a Linux build, eM Client and Mailbird do not either, and Apple Mail exists only on Apple hardware. Once you write down every machine you actually read mail on, the list usually shortens to two rows. Thunderbird is the row most people land on, and it is worth reading the full Outlook vs Thunderbird comparison before you commit, because what it gives up is Exchange, not features. Our longer nine app breakdown, with the situations where we recommend a competitor over ourselves, is in the roundup of the best apps for multiple email accounts.
Pick the row that describes you
Six versions of leaving Outlook, and what each one should buy
Only two of these six end with us, and we would rather say which than sell you the wrong thing and lose you in a month.
You want the same thing, minus Microsoft
Mail, calendar, contacts, tasks, one window, on a desktop. Buy eM Client if you want it to feel familiar, or run Thunderbird if you would rather pay nothing. Not us: we have no calendar and no contacts.
Your mail is a managed work mailbox
A Microsoft 365 tenant your employer controls. Your realistic options are new Outlook, classic Outlook while it lasts, or a client with OAuth such as Thunderbird or eM Client. We authenticate with a password, so we are out.
You just want the subscription gone
Check first whether you need to leave at all. New Outlook and Outlook for Mac both run without Microsoft 365 now, with ads. If ads are the dealbreaker, Thunderbird has neither ads nor a license fee.
You run Linux, or you might
Outlook has no Linux build and never has. Thunderbird is the serious desktop answer, BlueMail also ships Linux packages, and a browser board sidesteps the question because there is nothing to install.
You have six mailboxes and one morning
A personal address, a company address, a billing alias, two client domains and something old you cannot close. This is the case every desktop client handles by merging and none handles by sorting. This one is ours.
You move between machines you do not own
A locked down laptop, a shared desk, a Chromebook, a client site. Installing anything needs a ticket to IT. A board that lives in a tab travels with you and leaves nothing behind. Also ours.
If the last two rows were you
Four steps from Outlook to a sorted board
Nothing here moves or deletes your mail. It reads the IMAP protocol your provider already exposes, so Outlook can stay installed while you try this.
// 01
Check the mailbox type
Microsoft mailboxes will not connect to Inboxes at all -- not a managed Microsoft 365 account, and not a personal Outlook.com or Hotmail address. We authenticate over IMAP with an app password, and Microsoft has retired that login. If your mail lives at Microsoft, this is not the tool for you; the comparison below is still honest about where the alternatives stand.
// 02
Generate an app password
With two factor authentication switched on, providers issue a scoped credential rather than accepting your account password. Outlook.com, Gmail, iCloud and Yahoo all produce one from account security settings.
// 03
Connect every mailbox
Add each account with its IMAP host, port and credential. Common providers are detected, so in practice you paste an address and a password. Your mail stays where it is; nothing is migrated or exported.
// 04
AI sorts before you look
A model reads each arriving message and assigns it a category of Important, Newsletter, Notification, Spam, or Other. Archive and junk decisions push back to the IMAP server, so Outlook shows the same state.
Who this pays off for
Where leaving Outlook actually saves money
One mailbox at normal volume does not need any of this. These are the situations where the switch pays for itself in the first month.
Consultants billing several clients
One address per client domain, plus a personal one and a billing alias. They have to stay separate for the client, but the person reading them has one morning and no interest in five Outlook profiles.
Small firms off Microsoft 365
Mail on a hosting provider, a registrar or a small IMAP host, where Outlook is a habit rather than a requirement. Nothing about those mailboxes needs a Microsoft client, and the subscription is pure overhead.
Bookkeepers and accountants
Receipts, invoices and bank notices arrive across several addresses and have to be found again at quarter end. Receipts and payment confirmations land in Notification with a summary and tags attached on arrival, which beats a saved search across four Outlook data files.
Agencies holding client domains
Half a dozen custom domain mailboxes on different hosts, each with its own webmail and quirks. IMAP is the one thing they all have in common, which is what makes a single board possible at all.
Anyone dreading the cutover
If your workflow depends on COM add ins or a local PST, the cutover stage eventually removes it. Moving on your own schedule beats moving on Microsoft schedule, and there are years of notice to do it in.
People checking five junk folders
Every provider filters differently, so several mailboxes means several junk folders to check for the thing that got caught. One spam verdict applied consistently across all of them removes that chore.
Where we lose
Four reasons we are the wrong Outlook replacement
Outlook is a deep product and we are not a like for like swap for it. These four are the ones that send people back, so they belong before the pricing page, not after it.
Managed Microsoft 365 mailboxes generally will not connect. This is the big one on this page. Inboxes authenticates with a username and password or an app password, and Microsoft finished retiring basic authentication for Exchange Online in April 2026. A work or school mailbox on a Microsoft 365 tenant now refuses that connection regardless of which client is asking. Personal Outlook.com and Hotmail mailboxes still work in clients that hold a Microsoft login -- never in Inboxes, which uses an app password -- but Microsoft states it will fully remove basic authentication from Outlook.com as well and rely only on OAuth, so treat any Microsoft address as at risk rather than safe. If your Outlook holds a work mailbox and nothing else, stop here and look at Thunderbird or eM Client instead.
No calendar, no contacts, no tasks. Half of what Outlook does is not mail. Meetings, invitations, a shared address book, task lists and notes are all outside what we build, and swapping Outlook for us means finding homes for those elsewhere. eM Client and Thunderbird are the honest recommendations if a single window holding your week is the point.
Nothing installed means nothing offline. This runs in a browser tab, which is exactly what makes it work on a locked down laptop or a Chromebook, and exactly what makes it useless on a plane. There is no local mail store, no PST equivalent, no add in model and no menu bar presence. Classic Outlook remains far better at all of that.
We are more expensive than most of this page. Plans start at $29 a month flat, with 5 mailboxes on the entry plan and up to 120 on the largest, against a Thunderbird license fee of nothing and an eM Client pay once license at 59.95 dollars. If your goal is to spend less than Microsoft 365 charges you, several rows in the table above beat us on that alone. The case for paying us starts when the reading itself is the cost, not the license.
FAQ
Questions people ask about Outlook alternatives
What is the best alternative to Outlook?
It depends on what you are actually replacing. Thunderbird is the strongest pick if you want mail, calendar and contacts with no license fee. eM Client is the closest paid equivalent to the classic Outlook layout. Spark is the best cross platform option. If your problem is many mailboxes rather than one program, a browser based board fits better than any of them.
Is Outlook being discontinued?
No. The Outlook brand is not going anywhere, but classic Outlook for Windows is being phased out and replaced by new Outlook. Microsoft says existing classic Outlook installations under perpetual and subscription licensing stay supported until at least 2029. What is ending is the old program, not Outlook as a product.
What is replacing classic Outlook?
New Outlook for Windows, which is the Outlook web experience packaged as a Windows app, sharing one codebase across Windows, Mac and the browser. Microsoft is moving users through three stages: opt in, where it sits today, then opt out where new Outlook becomes the default, then cutover where switching back is no longer possible.
Is there a better email client than Outlook?
For a single Microsoft 365 mailbox with heavy calendar use, not really. Outlook is still the most complete option there. For anything else, several clients beat it: Thunderbird on filters and IMAP handling, eM Client on the suite experience without a subscription, Spark on phones, and a browser based board on machines you cannot install software on.
What can I use instead of Microsoft Outlook?
Thunderbird, eM Client, Mailbird, Spark, Canary Mail and Apple Mail all connect the same mailboxes Outlook does over IMAP. Thunderbird and Apple Mail cost nothing. eM Client and Mailbird sell a pay once license. Which one to pick comes down to whether you need a calendar, how many mailboxes you run and which machines you use.
Is there a free alternative to Outlook?
Yes, two good ones. Thunderbird is open source with no license fee and includes mail, calendar, contacts and the deepest filter engine on the desktop. Apple Mail comes with every Mac. Both connect unlimited IMAP accounts. eM Client also has a no cost tier, but it stops at two accounts and is licensed for personal use only.
What is the best Outlook alternative for Windows?
eM Client, if you want the classic Outlook shape kept: mail, calendar, contacts and tasks in one window, with a pay once license at 59.95 dollars in the US. Thunderbird is the pick if you would rather pay nothing and do not mind a denser interface. Mailbird suits people who want chat and calendar panes docked beside the message list.
What is the best Outlook alternative for Mac?
Apple Mail, for most people, because it is already installed and merges every account into All Inboxes at no cost. Beyond it, eM Client ships a Mac build with the full suite, Spark is the strongest option if you also want it on an iPhone, and Mimestream is the specialist choice when every mailbox you own is Gmail.
What is the best Outlook alternative for Linux?
Thunderbird, and it is not close. Outlook has never had a Linux build, and among serious desktop clients Thunderbird is the only one shipping first class Linux packages with mail, calendar and contacts together. BlueMail also runs on Linux. eM Client and Mailbird do not, so both are out on that platform.
Is Thunderbird better than Outlook?
On IMAP handling, filters and cost, yes. Thunderbird takes unlimited accounts, has Unified Folders for a combined view, and charges no license fee. Outlook is better on calendar and meeting workflows, on Exchange features and on anything involving a managed Microsoft 365 tenant. Most people switching from Outlook are leaving for the first list, not the second.
Can I still use classic Outlook?
Yes, for now. Microsoft states that existing classic Outlook installations through perpetual and subscription licensing continue to be supported until at least 2029, and administrators get at least twelve months notice before each migration stage. Classic Outlook is also still the only version that runs COM add ins and opens a full offline store.
Will an Outlook alternative work with my work email?
Only if it supports OAuth, also called modern authentication. Microsoft finished retiring basic authentication for Exchange Online in April 2026, so a managed Microsoft 365 work or school mailbox now refuses a plain username and password from any client. Thunderbird, eM Client, Spark and Apple Mail handle OAuth. Inboxes does not, so work mailboxes generally will not connect to us.
Do I need Microsoft 365 to use Outlook?
No. Both new Outlook for Windows and Outlook for Mac work without a subscription, connecting Outlook.com, Gmail, Yahoo, iCloud and generic IMAP accounts. The catch is advertising: without Microsoft 365 you get ads in the message list. A Microsoft 365 Personal subscription is $9.99 a month or $99.99 a year and removes them.
Related
Keep reading
Leave the program, keep the mail
Nothing is migrated and nothing is installed. Connect every mailbox you own over IMAP and let a model tag each message before you read it.