Disclosure up top: we make STAMP. We are biased. We will still tell you when something else is the better fit. The whole point of this list is that you should pick the right tool, not the one we ship.
We tested every major macOS email client over the last six weeks. Here is the working list, ranked by who they are for.
The shortlist
- STAMP. Triage-first, keyboard-driven, multi-account, on-device classification, $8/month. Best for: knowledge workers with three or more accounts and high volume.
- Superhuman. Keyboard-fast, AI-assisted, polished, $30/month. Best for: power users on Gmail or Outlook who want maximum polish and do not mind the price.
- Apple Mail. Free, native, unbothered. Best for: anyone with two accounts and under 50 emails a day.
- Hey. Opinionated bucket-based system, $99/year. Best for: people who want a fully different email metaphor and are willing to use a hey.com address.
- Spark. Free with paid tier, multi-account, decent triage. Best for: teams who want shared drafts and inbox.
- Mimestream. Native macOS Gmail client, $50/year. Best for: Gmail purists who want a Mac app instead of a browser.
- Mailspring. Open-source, free. Best for: tinkerers who want extensions and a price of zero.
- Outlook for Mac. Native, deep Microsoft 365 integration. Best for: corporate-365 environments.
Detailed take on each
STAMP
We will be quick about this since the rest of the site explains the bet. STAMP is a triage layer. It surfaces the seven threads that matter today across every account you connect, with on-device classification and tags that explain why. Keyboard-first. macOS-only for now. $8/month, locked at early access.
Pick STAMP if your problem is volume plus multiple accounts. If you are happy on Apple Mail with one account, do not switch. The whole point of this list is honest fits.
Superhuman
The OG premium client. Keyboard speed, Split Inbox, snooze, follow-up reminders, well-designed. Their AI features (Instant Reply, Auto-summarize) are the most mature in the category.
Limitations: $30/month is steep. Triage is per-account, not unified. Cloud-based AI processing is a privacy posture you will have to evaluate. Recently raised prices for new users. Read STAMP vs Superhuman for the head-to-head.
Apple Mail
The default. Native, free, fast. Multi-account works. Spotlight integration is excellent. Smart features (VIP, flags, focus modes) are useful but require manual setup.
Limitations: no triage layer, flat sorted-by-time list, weakest at high volume. We have a direct comparison post.
Hey
Hey, by the Basecamp team, takes the cleanest swing at rethinking email since Gmail in 2004. The Imbox / Feed / Paper Trail metaphor forces you to triage senders, not threads.
Limitations: requires a hey.com address (or the more recent Hey for Work for custom domains). Paid annually only. The opinionated bucket system is great if you buy into it and friction-y if you do not. We respect the swing.
Spark
Spark by Readdle is a solid free-tier client with good multi-account support, smart inbox grouping, and shared drafts on the team plan. Good fit for small teams that handle a shared inbox.
Limitations: triage is shallow. The smart-inbox categories are not as sharp as a real triage layer. Free tier has limits, paid tier is $4.99/month per user.
Mimestream
Mimestream is a native macOS Gmail client. It uses the Gmail API directly (not IMAP), so it understands Gmail labels, search operators, and threading the way Gmail intends.
Limitations: Gmail-only. If you have any non-Gmail accounts, Mimestream cannot help. $49.99/year. No deep triage layer beyond what Gmail provides.
If you have one Gmail and want a snappy Mac app, Mimestream is a good answer.
Mailspring
Open-source fork of the old Nylas client. Free, plus a paid Pro tier for extras. Reasonable basics, multi-account, snooze, send later.
Limitations: development pace is slow. Bugs persist. No on-device intelligence. Maintained by a small community. Pick this if you want zero cost and do not need polish.
Outlook for Mac
If you live in Microsoft 365, Outlook for Mac is fine. Native client, deep calendar and Teams integration, decent search.
Limitations: not great with non-Microsoft accounts. The interface is unchanged in spirit since 2007. Not designed for triage.
What we do not recommend in 2026
- Airmail. Stagnant. Ownership changes hurt it.
- Postbox. Discontinued.
- Thunderbird. Excellent for tinkerers, not for everyday productivity. The 2024 redesign helps but does not change the underlying philosophy.
- The Gmail web tab. Not a desktop app. We covered when to leave Gmail here.
Decision tree
If we had to pick one for a friend without knowing them, here is the rough flow:
- One Gmail, low volume → Apple Mail or Mimestream.
- Multiple accounts, high volume, willing to pay → STAMP.
- One account, want maximum polish, budget allows → Superhuman.
- Want a totally different metaphor → Hey.
- Team inbox sharing → Spark.
- Free, do not mind rough edges → Mailspring.
- Microsoft 365 shop → Outlook for Mac.
What to test for in any client
If you are evaluating any client, run these five tests in the first hour.
- Connect every account you have. Note any that fail or limp.
- Ask the client to show you the seven threads that matter today. If it cannot, you have no triage layer.
- Reply to a thread on a non-default account. Did it send from the right address?
- Search for an email from 2022 across all accounts. How fast?
- Press “?” to see the keyboard map. Is it real or token?
A client that fails any of those will fail you in production.
Where this list goes from here
We will update this list quarterly. Email clients are a slow-moving category but they do change. If we missed one, tell us.
For specific deep dives: STAMP vs Superhuman, STAMP vs Apple Mail, STAMP vs Gmail web.
Try STAMP free during early access. hello@stamp.email