Nuncio is in active development — building in the open, not shipping vapor.
Design comparison — architecture and roadmap, not a shipped product

Nuncio vs HEY Mail

HEY reinvented email triage, but only for addresses on its own platform, behind a $99/year subscription. We're building Nuncio to bring the same kind of opinionated screening and rules to any address you already have.

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.

Nuncio: Free & open source (in development)vsHEY Mail: $99 / Year Subscription

HEY Mailpricing is approximate — pricing as of 2026; check the vendor's site for current rates.

Bring Your Own Address

Nuncio syncs any standard IMAP/SMTP account you already have. HEY requires a $99/year subscription tied to a HEY-issued address.

Local Data, Not a Closed Cloud

Your mail lives in local SQLite, owned by a daemon you run. HEY's screening and workflow features run entirely inside HEY's own servers.

An Open Rule Language

NSQL rules can be authored and dry-run tested today as SQL-style statements, instead of a closed drag-and-drop screener.

Planned

One Contract, Future Clients

A desktop GUI, terminal TUI, and MCP client are planned as thin clients over the same gRPC API the CLI already uses.

Why We're Building It This Way

HEY's screening and workflow ideas are compelling, but they only work inside HEY's own cloud and require a HEY-issued address. Nuncio's design keeps your existing IMAP/SMTP accounts and puts the rule engine (NSQL) and the mail store on a daemon you run locally. The daemon, IMAP/SMTP sync, WORM audit ledger, export, and the local database's self-healing recovery are real and buildable from source today; NSQL rules firing on live mail and the additional client interfaces are the next milestones.

Design & Architecture Matrix

Nuncio's target design against HEY Mail today — planned items are labeled, not claimed as shipped.

Capability / DimensionNuncioHEY Mail
Pricing & Lock-In
Free & open source (in development)
$99/yr subscription
Protocol Support
IMAP, SMTP (JMAP/CalDAV planned)
HEY platform only
Local Data Ownership
Local SQLite, daemon you run
HEY cloud servers
Build & Run From Source
Yes
No
Terminal TUI Interface
Planned
No
AI Agent Access (MCP)
Planned
No
WORM Audit Ledger
Yes
No
Portable Export (MBOX/EML/JSON)
Yes
MBOX export only
Database Self-Healing
Yes
No

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 HEY Mail's $99 / Year Subscription.

View the full feature matrix