Mimestream is excellent for Gmail on Mac. Epistles is for the rest of your accounts and the rest of your devices

Mimestream is the best native Gmail client on the Mac. If one Gmail address on one Mac is your whole setup, you are already where you should be, and this page will not move you. Keep reading if your mail is split across Gmail and Outlook, or if you also check it on Linux, an iPhone, or an Android. That is where the two apps stop being comparable.

What Mimestream does well

Mimestream is a native AppKit app built only for Gmail, and it talks to the Gmail API instead of IMAP. That one decision is why it feels right. Labels stay labels instead of folders impersonating labels. Server-side filters are editable from inside the client. Promotions and Updates land where Gmail puts them, and aliases behave the way Google means them to. The macOS fit runs deep too: Spotlight, dark mode, the menu-bar extra, the dock badge, system share extensions, shortcuts that match every other Mac app.

Focusing on one provider pays off in a hundred small ways. Calendar invitations render and reply cleanly, because the team only had to make Google’s flavor work. Categories sort the way Gmail’s own web UI sorts them. Tracker blocking is built in. Several Gmail accounts share one window and a unified inbox that has been tuned for years. The app does one job and does not compromise on it.

It is also actively developed by a small team that talks openly about what it is building. For the app that holds your primary inbox, visible maintenance counts for more than a feature list. Mimestream has it.

Where Mimestream stops

Two limits define everything below, and Mimestream states both on its own site. It is macOS only, Monterey or newer: no iPhone, iPad, Linux, Windows, or web, and the team has said none are close. And it is Gmail only. Outlook, Microsoft 365, Fastmail, ProtonMail, iCloud, and plain IMAP hosts are not supported, and are not meant to be.

Pricing matches that focus: $4.99 a month or $49.99 a year, covering all your Google accounts on up to five devices. For Gmail on a Mac, that is a fair price for a good app.

What Epistles ships that Mimestream does not

Epistles is a different kind of product: a cross-platform, multi-provider client built on the premise that every account you answer to should live in one app, on every device you own.

It speaks six providers in their own protocols. Gmail goes through the Gmail API, Microsoft 365 through OWA, Fastmail through JMAP, and Proton through Proton's own API with OpenPGP decryption happening on the device. iCloud connects through a single app-password wizard that sets up IMAP mail plus CalDAV and CardDAV in one step, and anything else falls back to IMAP/SMTP. Each adapter loads on its own, so a Fastmail mailbox never pulls in Gmail's code and a Gmail mailbox never pulls in Proton's crypto. Nothing gets flattened to lowest-common-denominator IMAP on the way in.

It runs on macOS, Linux, Windows, iOS, Android, and the web, all shipping now and all from one codebase. Linux ships as signed APT, DNF, and Flatpak repos at repo.epistles.com; Windows as NSIS installers for x86_64 and aarch64; the web app lives at app.epistles.com. The engine, the SQLite cache, the adapters, and the vault are the same code underneath all of it.

Connected-account credentials sync through a zero-knowledge Cloud Vault. OAuth tokens, JMAP sessions, and IMAP passwords are wrapped on your device with a key derived from your Epistles password, then stored on our servers as ciphertext we cannot read. Sign in on a new Mac or phone, enter your password once, and the inboxes are already there. Proton is the exception: its passphrase and keys stay in your OS keychain and never touch the vault.

Mail lives in a local SQLite database, encrypted at rest by the operating system (FileVault, BitLocker, Data Protection, FBE) and searchable in milliseconds with no signal. Mimestream keeps mail on your Mac too, so both apps get that part right. Where they part ways is everything around the mail: Epistles reads calendar and contacts in the same client over CalDAV, CardDAV, JMAP, Google, Microsoft, and iCloud, so the meeting attached to a thread is one keystroke away. Mimestream is mail-only, and that is the sharpest single difference between them.

Pricing is two connected accounts free, then $35 a year for unlimited, with a 14-day trial that asks for no card up front. No per-seat creep, no enterprise tier, no analytics layer to feed.

Where Mimestream wins

On one Gmail account and one Mac, Mimestream is probably still the better pick. Its Gmail-API coverage is the most thorough we have used, feature for feature: categories, server-side filters, Schedule Send, Snooze, and aliases are all handled more completely than they are in Epistles. Its macOS polish has had years we have not. If that is the whole of what you want from a mail client, use it.

We also do not ship Snooze, Send Later, or Read Receipts yet. Snooze is waiting on relay work we would rather build properly than patch together per provider. Send Later is client-driven by design, which means the device that scheduled the send has to be awake when the time comes. Mimestream has all three today. We will too; we do not now.

Side by side

Platforms shipping today

Mimestream: macOS. Epistles: macOS, Linux, Windows, iOS, Android, web.

Email providers supported

Mimestream: Gmail. Epistles: Gmail, Microsoft 365, Fastmail (JMAP), ProtonMail, Apple Mail / iCloud (single ASP wizard provisions IMAP mail + iCloud calendar + iCloud contacts), IMAP/SMTP.

Native push

Both clients support sub-second push for Gmail. Epistles also supports OWA SignalR push for Microsoft 365 and JMAP push for Fastmail.

Calendar and contacts

Mimestream: calendar invitation responses, no full calendar or contacts. Epistles: full calendar and contacts via CalDAV, CardDAV, JMAP, Google, Microsoft, and Apple iCloud, with a single Apple ID + ASP wizard for iCloud mail, calendar, and contacts.

Apple Watch app

Mimestream: no. Epistles: yes, archive, snooze, voice and template reply, “Reply & Done,” pin, forward to contact, agenda with RSVP, plus WidgetKit complications.

Wear OS app

Mimestream: macOS-only, no mobile or watch. Epistles: yes, Galaxy Watch, Pixel Watch, any Wear OS 3+ device, with the same triage feature set as Apple Watch and an inbox tile.

Cross-device account sync

Mimestream: per-device account setup. Epistles: zero-knowledge Cloud Vault carries connected-account credentials between devices, encrypted under your Epistles password.

Local-first storage

Both store mail on the device. Both work offline. Both encrypt at rest.

Snooze, Send Later, Read Receipts

Mimestream: shipping. Epistles: roadmap.

Pricing

Mimestream: $4.99/mo or $49.99/yr; all Google accounts; up to 5 devices. Epistles: free for 2 accounts; $35/yr Pro for unlimited; 14-day free trial, no card.

Telemetry

Both clients are quiet by default. Epistles ships zero analytics, zero crash reporting SDKs, zero metrics; only functional API calls.

Who should pick which

Read only Gmail, only on a Mac, and want Snooze and Schedule Send today? Mimestream. The polish rewards a single-vendor workflow, and for that person it is genuinely the better app right now.

Carry more than one provider, though, and Mimestream cannot follow you. A work Microsoft 365 mailbox next to a personal Gmail, a Fastmail address that has outlasted three jobs, a ProtonMail for the sensitive work: Epistles keeps each one in its own native shape instead of forcing them through a single pipe.

And if you use Linux, or read mail on iOS or Android, the decision is made for you. Mimestream does not ship there. Epistles does, from the same codebase, with the same shortcuts and the same vault carrying your accounts between devices.

If you do switch

Switching off Mimestream is easy, because both apps leave your mail at Google. There is no local archive to move and no draft format to convert. Reconnect your Gmail accounts in Epistles, add your other providers, and the mail you were just reading is there. Filters, labels, and aliases stay on Google's side, and Epistles reads them through the same API.

Bottom line

Mimestream is a careful Mac app from a small team that clearly loves the craft, and we hope it stays exactly that. Epistles is a different shape of product for a different shape of inbox. If yours looks like the one this page describes, the front door is here.