Kitsmith / Email Clients
MacEmail Clients
5 hand-verified email clients for Mac.
Mozilla Thunderbird and Proton Mail are the two privacy-first free options here, from different angles. Thunderbird is free forever, funded entirely by donations under MZLA, a for-profit Mozilla subsidiary structured to sustain it long-term — the project states it doesn’t collect personal data, sell inbox ads, or train AI on private messages. Proton Mail, from Swiss company Proton AG, pitches zero-access encryption instead — it states it cannot read your inbox on any plan, paid or free — with a genuinely usable free tier (1 GB storage, 1 address, forever) before paid plans from $3.99/mo billed annually add more storage and bundle Proton’s VPN, Drive, and password manager.
Spark, Mimestream, and Canary Mail all lean into AI triage, but differ sharply on scope and billing. Spark (Readdle) is free with unlimited accounts and a Smart Inbox, with its opt-in AI writing/summarization features metered by a monthly credit quota that scales with a $10/mo Plus or $20/mo Pro tier. Mimestream is the narrowest and most opinionated: Gmail accounts only, built on the Gmail API rather than generic IMAP for native categories and labels, subscription-only at $49.99/yr with no one-time-purchase option at all — the developer has published its own reasoning for that choice. Canary Mail covers the middle ground: a real free tier (unified inbox, unlimited accounts on up to 2 devices), with paid Growth and Pro+ tiers — the latter adding PGP encryption — sellable either as a subscription or a one-time lifetime purchase, unusual for an AI-forward email app.
All 5 apps
No apps match those filters.
Mozilla Thunderbird
Free forever (donation-supported)A free, open-source, donation-funded email client from the Mozilla family — unified inbox, calendar and contacts, and no ads or AI training on your mail.
Proton Mail
Free (1 GB); Mail Plus $3.99/mo billed annually ($47.88/yr); Proton Unlimited $9.99/mo billed annually ($119.88/yr)End-to-end encrypted email from Swiss privacy company Proton AG — free tier available, with paid plans bundling calendar, VPN, and storage.
Spark
Free; Plus $10/mo ($8.25/mo billed yearly); Pro $20/mo ($16.58/mo billed yearly); Enterprise customA cross-platform email client from Readdle with AI writing, summarization, and inbox-prioritization tools — free to start, with paid tiers for AI quota and team collaboration.
Mimestream
$49.99/yr or $4.99/mo, 14-day free trial; no one-time purchase optionA native Mac email client built specifically for Gmail, using the Gmail API directly rather than IMAP — subscription-only, 14-day free trial.
Canary Mail
Free; Growth $3/mo billed yearly ($36/yr); Pro+ $10/mo billed yearly ($100/yr); both paid tiers also sell as a one-time lifetime purchaseAn AI email client with a built-in calendar, read receipts, and PGP encryption — free plan available, paid tiers add AI copilot and advanced security.
The verdict
We haven't singled out a top pick here yet — every one of the 5 is hand-verified, so start wherever your job description points you. 1 of the 5 is free, and 2 are open source. Paid options run $49.99.
Mac email clients — questions people ask
Is there a genuinely free email client for Mac?
Thunderbird is free forever, donation-funded, with no paid tier at all. Proton Mail’s free plan (1 GB storage, 1 address) is also free forever, though its higher tiers unlock more storage and bundled apps. Spark and Canary Mail both have real, unlimited-account free tiers too, with paid AI/security add-ons.
Is there a Mac email client built specifically for Gmail?
Mimestream — it connects through the Gmail API rather than generic IMAP, matching Gmail’s own categories, filters, and labels. It only supports Gmail accounts, and it’s subscription-only ($49.99/yr or $4.99/mo) with no one-time purchase.
Which of these email clients offer a one-time purchase instead of a subscription?
None offer email itself as a pure one-time purchase, but Canary Mail’s paid Growth and Pro+ tiers can both be bought as a one-time lifetime license instead of billing monthly or yearly — the only one of the five with that option.
Is there an end-to-end encrypted email client for Mac?
Proton Mail encrypts on every plan, including free, and states it cannot read inbox contents at all. Canary Mail’s Pro+ tier ($10/mo billed yearly, or a lifetime purchase) adds PGP encryption on top of its AI features.