Spark is an affordable cross-platform client, but the AI feels light and your credentials live on Readdle's servers. Here are five alternatives across AI depth, privacy and platform reach.
Spark Mail is a genuinely good, affordable email client with a strong free tier and broad platform support. The catches: the AI is lighter than dedicated tools, it stores your credentials on Readdle's servers, and it makes you faster without reducing how much email you personally handle. If you want an agent that does the work after triage, the Alkmist Inbox Agent is the strongest alternative: it ranks your inbox across Outlook and Gmail, drafts in your voice and chases follow-ups, with EU hosting. For AI-native Gmail, Shortwave. For privacy-first, Canary Mail.
Spark Mail has real strengths. The common reasons people go looking for an alternative:
Reviewers say Spark's AI is impressive on paper but gets underused in practice, and paid plans put quotas on it.
Spark stores your email credentials on its servers, which is a real consideration for confidential mail.
Spark speeds up writing, but you still read, decide and reply to every message yourself; it does not chase or organise the work.
The Windows and Android apps lag the polished Mac and iOS experience.
Four questions that decide whether a tool actually sticks.
Layering onto Outlook and Gmail beats replacing your client or locking you to one ecosystem.
Labelling tidies the inbox. Ranking tells you the few things that actually need you today.
Drafting is table stakes. Chasing the threads that go quiet is what stops things slipping.
Watch for annual lock-in, per-seat costs, credit meters and overage fees in the fine print.
Ranked by how much work they take off your plate, with honest notes on where each falls short.
Reads every email in Outlook and Gmail, ranks the few that need you, drafts in your voice, and chases stalled follow-ups on its own. Groups email, docs and tasks into projects, with a built-in assistant (voice coming soon) and one Inbox Health score. EU-hosted, never trains on your mail, never sends without your click.
Trade-off: no in-meeting notetaker, and access is via waitlist while it rolls out.
Built by ex-Google Inbox engineers, it makes AI search, summaries, drafting and categorisation the default state of the inbox. Free tier; paid from about $14 per month.
Trade-off: Gmail only, no Outlook or IMAP, and it replaces your client.
A keyboard-first client with sub-100ms actions, AI drafts in your voice, instant replies and thread summaries. Works in Gmail and Outlook. Now owned by Grammarly.
Trade-off: it replaces your client, it is the priciest option here (from about $25 per user per month), and it is a single-player tool.
An Apple-friendly client with on-device AI for summaries and drafts, end-to-end encryption and a focused inbox. Paid from about $49 per year.
Trade-off: it replaces your client and leans Apple-first, with lighter follow-up and project features.
Sits in front of any IMAP inbox (Gmail, Outlook, Apple Mail) and learns which mail matters, moving the rest into smart folders. It also tracks emails you sent but did not get a reply to. From about $7 per month per inbox.
Trade-off: it filters, it does not draft, rank a single priority list, or chase follow-ups for you.
| Tool | Best for | Works in |
|---|---|---|
| Alkmist Inbox Agent (Pidgy) | Closing the loop across Outlook + Gmail | Outlook + Gmail |
| Shortwave | AI-native Gmail | Gmail only |
| Superhuman | Raw speed | Gmail + Outlook (client) |
| Canary Mail | Privacy-first client | Gmail, Outlook, iCloud |
| SaneBox | Lightweight filtering | Gmail, Outlook, IMAP (layer) |
The Alkmist Inbox Agent reads Outlook and Gmail, hands you the five that need you, and chases the rest. Join the waitlist for early access.
