Nuncio vs Microsoft Outlook
The new Outlook is a web view wrapped in a subscription, with ads in the free tier and telemetry throughout. We're building Nuncio as a minimal, memory-safe Rust daemon with no ad network and no telemetry pipeline, full stop.
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.
Microsoft Outlookpricing is approximate — pricing as of 2026; check the vendor's site for current rates.
Memory-Safe Rust Core
The engine is written in Rust with unsafe code forbidden by the workspace lint gate — a different foundation than the new Outlook's web-view shell.
No Ads, No Telemetry
Nuncio's engine contains no ad network, no diagnostic telemetry pipeline, and no sponsored placements in your inbox.
A Scriptable CLI, Today
nuncio-cli is a real, scriptable gRPC client you can build and run right now. Outlook has no command-line surface at all.
An Open Rule Language
NSQL rules can be authored and dry-run tested today as SQL-style statements — with live rule firing on synced mail on the roadmap.
Why We're Building It This Way
Microsoft's transition to the web-based 'New Outlook' brought inbox ads and mandatory account telemetry along with cloud sync. Nuncio's design starts from a different place: a Rust daemon (nunciod) with unsafe code forbidden by the build's own lint gate, no ad network, and no diagnostic pipeline. The daemon, IMAP/SMTP sync, WORM audit ledger, and export already build and run from source today; live-firing NSQL rules and at-rest encryption are the next milestones.
Design & Architecture Matrix
Nuncio's target design against Microsoft Outlook today — planned items are labeled, not claimed as shipped.
| Capability / Dimension | Nuncio | Microsoft Outlook |
|---|---|---|
| Pricing Model | Free & open source (in development) | Microsoft 365 subscription (~$9.99/mo or ~$99.99/yr) |
| Ads & Telemetry | None in the engine | Ads in free tier; telemetry in paid tiers |
| Build & Run From Source | Yes | No |
| Scriptable CLI | Yes | No |
| Terminal TUI Interface | Planned | No |
| AI Agent Access (MCP) | Planned | No |
| WORM Audit Ledger | Yes | No |
| NSQL Automation Engine | Author & dry-run test todayIn progress | Basic rules |
| At-Rest Body Encryption | Planned | Unencrypted local cache |
| Portable Export (MBOX/EML/JSON) | Yes | PST export only |
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 Microsoft Outlook's Microsoft 365 Subscription / Ad-Supported.