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

Mimestream is the most polished native Gmail client on macOS. If a single Gmail address on a Mac is the whole picture, you are already at the right destination and this page will not change your mind. If your inbox spans Gmail and Outlook, or if you also read mail on Linux, an iPhone, or an Android, the trade-offs are different and worth naming plainly.

What Mimestream does well

Mimestream is a native AppKit application built specifically for Gmail. It uses the Gmail API rather than IMAP, which means Gmail's own concepts arrive intact: labels are labels, not folders pretending to be labels, server-side filters are editable from the client, categories like Promotions and Updates carry over, and aliases work the way Gmail intends. The polish is real. Touch Bar (when it existed), Spotlight, dark mode, the menu bar extra, dock badge, keyboard shortcuts that match the rest of macOS, services and share extensions: these are not bullet points, they are the texture of using the app.

The single-vendor focus pays for itself in a hundred small places. Calendar invitations render and respond cleanly because the team only had to make Gmail's invitation flavour work. Inbox categories sort the way Gmail's web UI sorts. Tracker prevention is built in. Multiple Gmail accounts coexist in one window with a unified-inbox option that has been tuned over years. When Federico Viticci and other careful Mac power users praise Mimestream, this is what they are praising. The app does one thing and does it without compromise.

Mimestream is also actively developed and openly discussed by its small team, which matters more than feature lists. A client you will trust with your primary inbox should be one whose maintenance you can see. Mimestream qualifies.

Where Mimestream stops

Two constraints shape the rest of this page, and both are stated plainly on Mimestream's own site. It runs on macOS only, requiring Monterey or newer. There is no iPhone, iPad, Linux, Windows, or web app, and the team has been candid that none are imminent. It also connects to Gmail only. Outlook, Microsoft 365, Fastmail, ProtonMail, iCloud, and arbitrary IMAP hosts are not supported, by design.

Pricing reflects the focus: $4.99 a month or $49.99 a year, with all your Google accounts on up to five devices. For someone who reads only Gmail and reads it only on a Mac, that is a fair price for a fine app.

What Epistles ships that Mimestream does not

Epistles is a different kind of product. It is a cross-platform, multi-provider mail client whose first commitment is that every account you answer to should live in one client on every device you use.

Five providers, native protocols. Gmail through the Gmail API, Microsoft 365 through MS Graph, Fastmail through JMAP, ProtonMail through Proton's API with OpenPGP decryption on device, and any IMAP/SMTP host as the catch-all. Each adapter ships and loads independently, so a Fastmail-only mailbox never downloads Gmail code, and a Gmail-only mailbox never downloads Proton's crypto. Threads, labels, flags, and push are spoken in each provider's own dialect rather than flattened to a lowest-common-denominator IMAP.

Four platforms today, two more in build. macOS, Linux (as both a signed .deb and an AppImage), iOS, and Android are shipping in early access. Windows and a browser-based web app at app.epistles.com are in development and have honest "coming" badges, not pretend launch dates. The core engine, the SQLite cache, the protocol adapters, and the Cloud Vault are one codebase across all of them.

A zero-knowledge Cloud Vault. The credentials for every account you connect, OAuth refresh tokens, JMAP session blobs, IMAP passwords, are wrapped on your device with a key derived from your Epistles password and stored on our servers as opaque ciphertext bytes we cannot decrypt. Sign in on a second Mac or a new phone, type your password once, and your inboxes are already there. Proton is carved out: its mailbox passphrase and OpenPGP material live in your OS keychain only and never travel through the vault, by design.

Local-first storage. Every message lives in a local SQLite database, encrypted at rest with AES-256-GCM, searchable in milliseconds with no signal required. Mimestream is also local-first in the sense that mail lives on your Mac, which is one of the things both products get right.

Calendar and contacts in the same client. CalDAV, CardDAV, JMAP, Google, and Microsoft calendar and address book protocols are read alongside the mail, so the meeting attached to a thread sits one keystroke away.

Pricing that tracks the project, not the seat. Three connected accounts on Free. Pro is $35 a year, with a fifteen-day trial that asks for no card up front. No per-seat creep, no enterprise tier, no analytics layer to feed.

Where Mimestream wins

This section earns the rest of the page, so we are going to be careful with it. If you have one Gmail account and one Mac, Mimestream is probably the better choice today. Its Gmail-API depth is, on a feature-by-feature basis, the most thorough we have used. Its handling of Gmail categories, server-side filters, Schedule Send, Snooze (yes, Mimestream ships Snooze; we don't yet, and we explain that below), and aliases is more mature than ours. Its macOS integration has had years of polish that a younger application has not had time for. If those things are the entirety of what you want from a mail client, you should use Mimestream.

We also do not yet ship Snooze, Send Later, or Read Receipts. Snooze is waiting on a piece of relay infrastructure that we want to build correctly rather than ship as a per-provider patchwork. Send Later is, by deliberate design, client-driven in our architecture, which means the device you scheduled the send on has to be available when the time arrives. Mimestream ships these. We will, but they are not in the box today, and that is honest.

The matrix, plainly

Platforms shipping today

Mimestream: macOS. Epistles: macOS, Linux, iOS, Android. (Epistles Windows and web in development.)

Email providers supported

Mimestream: Gmail. Epistles: Gmail, Microsoft 365, Fastmail (JMAP), ProtonMail, IMAP/SMTP.

Native push

Both clients support sub-second push for Gmail. Epistles also supports MS Graph 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.

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 3 accounts; $35/yr Pro for unlimited; 15-day 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

If you read Gmail and only Gmail, on a Mac and only on a Mac, and you want Snooze and Schedule Send today, Mimestream is the right choice. The polish rewards a deliberate, single-vendor workflow. Pay for it. We are not pretending to be a strict superset; we genuinely believe that for this profile of user, Mimestream is better today.

If you carry more than one provider, a work Microsoft 365 mailbox alongside a personal Gmail, a Fastmail account that has outlasted three jobs, a ProtonMail for the political work, then Mimestream cannot help and Epistles can. The multi-provider story is the wedge, and we picked native protocols precisely so that nothing flattens on the way in.

If you also use Linux, or you read mail on iOS or Android, the choice is forced. Mimestream does not ship there. Epistles does, today, from the same codebase, with the same shortcuts and the same Cloud Vault carrying your connected accounts between devices.

If you do switch

Switching from Mimestream is unusually painless because both clients leave your mail at Google. There is no local archive to migrate, no draft format to convert. Reconnect your Gmail accounts in Epistles, sign into your other providers, and the same mail you were just reading shows up. Filters, labels, and aliases stay where they live, on the Gmail side, and Epistles reads them through the same API.

A line at the end

Mimestream is a careful, considered Mac application made by a small team who clearly love their craft. We hope it stays that way for a long time. Epistles is a different shape of product for a different shape of inbox. If yours is the shape this page describes, our front door is here.