Price, accounts, and what each one is built with
Prices checked September 2026 on each vendor’s own site or Mac App Store listing, in US dollars, before tax, on annual billing where the vendor offers it. These move, so confirm the plan as well as the number before you buy.
| Client | Price | Accounts | Built with | Best for |
|---|---|---|---|---|
| Apple Mail | Free with macOS | iCloud, Google, Exchange, any IMAP | Native (Apple) | Best free default |
| Mimestream | $49.99/yr per user ($4.99/mo monthly) | Gmail and Google Workspace only | Native (Swift) | Best for Google Workspace |
| Microsoft Outlook | Free app; Microsoft 365 with desktop apps $14/mo per user | Microsoft 365, Outlook.com, Gmail, iCloud, Yahoo, IMAP | Native (per Microsoft) | Best for Microsoft 365 |
| Spark | Free; Plus $99/yr, Pro $199/yr per user | Google, iCloud, Exchange, Outlook, Yahoo, IMAP | Electron | Best for a small team sharing an address |
| Superhuman | $33/mo per user (Business, annual) | Gmail and Outlook only | Electron | Best when email is the job and cost is secondary |
| Canary Mail | Free; Growth $36/yr, Pro+ $100/yr | Gmail, Microsoft 365, iCloud, Exchange, IMAP | Native (per Canary) | Best encryption and read receipts for the money |
| Airmail | $49.99/yr (Pro) or $49.99 once (Business) | iCloud, Gmail, Exchange, Outlook.com, IMAP, POP | Native | Most customisable |
| MailMate | $10 every 3 months | Any IMAP host, including Microsoft 365 over IMAP | Native (AppKit) | Best for keyboard-driven IMAP power users |
| eM Client | $49.95/yr or $79.95 once, per device (Business) | Google, Microsoft 365, Exchange, iCloud, IMAP | Cross-platform .NET | Best for a mixed Windows and Mac office |
| Thunderbird | Free (donation funded) | IMAP, POP, Exchange (EWS), Microsoft 365 (Graph) | Mozilla Gecko | Best free and open source |
| Proton Mail | $47.88/yr (Mail Plus, one person) | Proton accounts only | Electron | Best if you will move your mail to an encrypted host |
Two questions settle most of it
- Where does your mail live? Mimestream opens only Google accounts, Superhuman only Google and Microsoft, and Proton only Proton. If your business mail is split across hosts, those three are out before features come into it.
- Will anyone else answer it? If yes, look first at Spark, Superhuman and Canary, which build shared threads, comments or shared inboxes into the client itself. If no, you are paying for speed, privacy or polish, and Apple Mail sets a high bar for free.
Native or not comes third. It matters for memory, launch time and whether the app behaves like the rest of macOS, and it matters less than an account the client cannot open.
The eleven, ranked
1. Apple Mail: Best free default
Already on every Mac, genuinely native, and it opens every account type a small business is likely to have: iCloud, Google, Exchange and any IMAP host. It schedules sends, unsends, brings a message back to the top of the inbox when you ask it to remind you, and Mail Privacy Protection stops tracking pixels telling senders when you opened their email. For one person with two or three addresses it is enough more often than the rest of this list would like you to think.
The catch: No saved replies or templates, no read receipts, and nothing for a second person: no shared inbox, no assignment, no comments on a thread. Everything it knows about a conversation is read or unread, archived or not. On Microsoft 365, read the EWS deadline further down before relying on it.
2. Mimestream: Best for Google Workspace
Written in Swift by a company whose founder spent seven and a half years at Apple leading teams on Mail, and built on the Gmail API rather than IMAP, so labels, inbox categories, server-side filters, aliases and vacation responses behave exactly as they do in Gmail. Templates take variables that open a fill-in form. It keeps your data and tokens only on your Mac and talks to Google directly, with no sync service in between, and it blocks trackers from more than 75 services. A 14-day trial needs no card.
The catch: Gmail and Google Workspace only. If any of your business mail lives at iCloud, Microsoft 365 or another IMAP host, Mimestream cannot open it. Team licences exist for billing, but there are no shared inboxes or comments.
3. Microsoft Outlook: Best for Microsoft 365
If your business runs on Microsoft 365, this is the client made by the company that runs your mailbox and your calendar, and Microsoft describes the current version as crafted natively for Mac. It also opens Gmail, iCloud, Yahoo and IMAP accounts, so a mixed setup does not rule it out, and the app itself costs nothing.
The catch: Free with personal accounts means ads unless you pay for a premium subscription. A work Microsoft 365 mailbox needs a plan: Business Standard, the one Microsoft lists with the desktop apps, is $14 per user a month on annual billing, while Business Basic at $7 lists web and mobile Outlook only. It is also a 1.2 GB download.
4. Spark: Best for a small team sharing an address
The most complete set of team features here at a small-business price. The free plan already has scheduled send, snooze, reminders, a unified inbox and private comments on a thread; Plus adds templates and shared templates; Pro adds shared inboxes for addresses like sales@ or support@, and read statuses. It opens nearly any account a business uses.
The catch: The Mac app is Electron, which Readdle chose so one codebase could ship on Mac and Windows. Push notifications and the team features run through Readdle’s servers, which hold access to each account you connect, so your mail is linked to a third party and not only to your Mac. Shared inboxes need Pro, not Plus.
5. Superhuman: Best when email is the job and cost is secondary
Built for speed on Gmail and Outlook accounts: keyboard first, a split inbox that puts your team and VIPs ahead of everything else, a reminder when someone has not replied by the date you chose, read statuses, and snippets you can share with a team. You can share a live view of any thread and colleagues can comment on it even if they do not use Superhuman, and its AI drafts replies and triages the inbox.
The catch: The most expensive client here by a distance: $33 per user a month on annual billing or $40 monthly, because Mail is sold only in the Business and Enterprise plans, bundled with Grammarly, Docs and Go. No iCloud or IMAP accounts. The Mac app is Electron.
6. Canary Mail: Best encryption and read receipts for the money
Read receipts, send later and an AI copilot arrive on the Growth plan at $36 a year. Pro+ adds PGP encryption, SecureSend (which Canary sells for HIPAA use), and phishing, impersonation and misdirected-email protection. Canary also says a shared inbox with assignments is available on every plan, and that your email is not used to train AI models.
The catch: There is no monthly plan: it is a year up front or a lifetime licence. The free plan has only a lite version of read receipts. And a read receipt from any client can report an open that never happened, for the reason in the questions below.
7. Airmail: Most customisable
A 2017 Apple Design Award winner built to be bent to your workflow: custom actions that chain several steps into one, rules that sync between Macs over iCloud, AppleScript, and plugins for read receipts and S/MIME or GPG encryption. Since June 2026 it can also connect to AI assistants through an MCP server that runs on your Mac, with every assistant approved by you and limited to the actions you allow.
The catch: Airmail Pro is $49.99 a year or $7.99 a month in the US App Store. The separate Airmail for Business is $49.99 once, keeps all data on your device with no analytics, but leaves out send later. Its App Store reviews include complaints about sync reliability and slow support replies.
8. MailMate: Best for keyboard-driven IMAP power users
A native Mac client for people who want to drive email from the keyboard, with Markdown composition, search conditions you can drill into, smart mailboxes, automatic signature handling, and OpenPGP and S/MIME built in. It speaks standard IMAP to any host, with OAuth sign-in for Office 365, Outlook.com, Fastmail and Yahoo.
The catch: Business use requires the paid mode, $10 every three months. Its own site says it is not for everyone, and it means it. There is no iPhone app, and releases are slow: the recommended download is a beta from July 2025, and the last full public release is more than four years old.
9. eM Client: Best for a mixed Windows and Mac office
The longest feature list here for a business on both Windows and Mac: full Exchange and Microsoft 365 support alongside Google, iCloud and IMAP, with calendar, contacts, tasks and notes in the same app. Templates, QuickTexts, send later, watch for reply, mass mail, and PGP and S/MIME encryption are all built in, and the licence can be bought outright as well as by the year. If you are replacing Postbox: eM Client bought Postbox in 2024, ended its development, and offered its customers a discount to move.
The catch: It is a .NET app that shares its code with the Windows version, and the Mac build ships its own Windows Forms layer and a Chromium-based renderer rather than using macOS’s own. The free licence excludes commercial use, so a business needs the Business licence, priced per device rather than per person.
10. Thunderbird: Best free and open source
Free, open source and funded by donations, with OpenPGP built in. It speaks IMAP and POP to any host, Exchange through EWS since late 2025, and, as of September 2026, Microsoft 365 through Microsoft’s Graph API, ahead of Microsoft disabling EWS on Microsoft 365 from 1 October 2026.
The catch: It runs on Mozilla’s Gecko engine rather than AppKit, so it looks and behaves like the cross-platform app it is. Its Exchange and Microsoft 365 support covers email only for now: calendars and contacts over those protocols are still being built.
11. Proton Mail: Best if you will move your mail to an encrypted host
Proton is a mail host with zero-access encryption, and its Mac app is the way into a Proton mailbox. Mail Plus, $47.88 a year for one person, includes the desktop app and one custom domain; team plans are priced per user, with Workspace Standard at $12.99 a user a month on annual billing. Bridge, on any paid plan, lets you keep Apple Mail, Outlook or Thunderbird as the client instead.
The catch: It is not a client for the mailbox you already have. The app opens Proton accounts only, so choosing it means moving your domain’s mail to Proton. The desktop app is Electron.
A deadline if your business is on Microsoft 365
Microsoft is retiring Exchange Web Services (EWS), the older protocol many Mac clients use to reach an Exchange mailbox. In Microsoft 365 it is disabled by default from 1 October 2026, unless an administrator keeps it on, and switched off for good on 1 April 2027. Microsoft says its own apps have moved or nearly moved to its Graph API.
University IT departments preparing for the change list Apple Mail’s Exchange accounts among the affected apps, and one reports that Apple is updating Mail to use Graph. Until that update ships, Outlook for Mac is the safe choice for a Microsoft 365 mailbox, and before you commit to any other client on this list, ask its maker whether it still depends on EWS.
If most of your business email is customers
Every client above understands mail as read or unread, archived or not. For a business whose inbox is mostly customers, that misses the state that costs money: you fixed the problem, and the customer has not been told. The thread is archived, so it looks exactly like one that ended well.
Moorline is a native Mac app for that part of business email, and it is not a mail client. It reads the mailbox you already have and works alongside whichever client you chose above, keeping each customer on a list until the work is handled and the customer has been told. Saved replies sit one keystroke away on ⌘; (the customer support email templates are a place to start), Stripe context is optional and read-only, and your data stays in a file on your Mac, so it works offline.
It connects to Gmail and Google Workspace with OAuth, and to iCloud, Fastmail, Zoho and other IMAP hosts with an app password. Microsoft 365 and Outlook.com are not supported, so if you picked Outlook above because your business runs on Microsoft, Moorline cannot read that mailbox yet. It is built for one person, not a team, at $9 a month on macOS 15 or later. For how it compares with help desks and shared inboxes, see the best customer support apps for Mac.
Questions people actually ask
What is the best email client for a small business on a Mac?
It depends on where your mail lives. On Google Workspace, Mimestream at $49.99 a year per user. On Microsoft 365, Outlook for Mac, whose app is free. With a mix of accounts and no budget, Apple Mail. For a small team sharing an address like support@, Spark Pro at $199 a year per user. For encryption, Canary Pro+ at $100 a year.
Is Apple Mail good enough for business email?
For one person, often yes. It is native, free, opens iCloud, Google, Exchange and IMAP accounts, and can schedule, unsend and remind. What it lacks is everything a business eventually wants from a client: saved replies or templates, read receipts, and any way for a second person to share, assign or comment on mail. On Microsoft 365, check that Mail no longer depends on EWS, which Microsoft starts disabling on 1 October 2026.
Which Mac email clients are native rather than Electron?
Native: Apple Mail, Mimestream (Swift), MailMate (AppKit), Airmail, Canary Mail and Outlook, which Microsoft describes as built natively for Mac. Electron: Spark, Superhuman and the Proton Mail desktop app. eM Client is a cross-platform .NET app shared with Windows, and Thunderbird runs on Mozilla’s Gecko engine.
Are read receipts in Mac email clients reliable?
Not fully. Spark Pro, Superhuman and Canary detect opens through remote content in the email. When a recipient uses Apple Mail with Mail Privacy Protection turned on, Mail downloads remote content privately in the background when the message arrives, not when it is read, so an open recorded for that person can mean delivered rather than read.
What is the best free email client for Mac for business use?
Apple Mail, then Thunderbird, which is open source and now reaches Microsoft 365 through the Graph API. Spark and Canary also have free plans that work with business accounts. Check the licence before choosing a free tier: eM Client’s free licence excludes commercial use, and MailMate requires its paid mode for any business relying on it.