Nuncio vs Canary Mail
Canary Mail routes AI features through proprietary cloud endpoints. We're building Nuncio around a different idea: an MCP gateway that lets AI agents touch your mail only through capability policies and an audit trail you control locally.
Nuncio is pre-alpha. Rows below marked Planned are architecture we are actively building, not something you can use yet — see the roadmap for status.
Canary Mailpricing is approximate — pricing as of 2026; check the vendor's site for current rates.
A Gateway, Not Cloud AI
The plan: an MCP client that lets AI agents work with your mail through a governed local gateway, never by routing your messages to a third-party AI service.
WORM Audit Ledger, Today
Every account and rule mutation is already recorded in an immutable, hash-chained audit log you can inspect and verify yourself.
Open Source, Fully Inspectable
Every line of the engine is public on GitHub under MIT / Apache-2.0. Canary Mail is closed-source and commercially licensed.
Local-First Storage
Mail lives in local SQLite, owned by a daemon you run yourself — not synced through a vendor's servers to power AI features.
Why We're Building It This Way
Canary Mail's AI features send message context to cloud AI APIs with no user-configurable capability policy. Nuncio's design keeps that decision local: an MCP client (on the roadmap) would broker every agent action through the same daemon that already owns your mail, with fine-grained capability flags and an immutable WORM audit trail. The audit ledger, local SQLite storage, and open-source engine are real today; the MCP gateway itself is the next milestone, not a shipped feature.
Design & Architecture Matrix
Nuncio's target design against Canary Mail today — planned items are labeled, not claimed as shipped.
| Capability / Dimension | Nuncio | Canary Mail |
|---|---|---|
| License & Transparency | Open source (MIT/Apache-2.0) | Closed proprietary |
| AI Agent Access Model | Local gateway, policy-governedPlanned | Cloud AI processing |
| WORM Audit Ledger | Yes | No |
| Build & Run From Source | Yes | No |
| Terminal TUI Interface | Planned | No |
| NSQL Server-Side Rules | Author & dry-run test todayIn progress | Basic smart filters |
| At-Rest Body Encryption | Planned | PGP / local database |
| Portable Export (MBOX/EML/JSON) | Yes | Limited export |
| Cross-Platform (engine + CLI) | macOS, Windows, Linux | macOS, Windows, iOS, Android |
Watch It Get Built, Don't Just Wait For It
Nuncio isn't installable by end users yet. It will be free and open source under MIT / Apache-2.0 — no account, no subscription, no lock-in vs Canary Mail's $36-$100 / Year (Growth/Pro+).