About

zsmtp is presented as a zero-knowledge SMTP mail transfer agent.

For this site, that framing means the transport layer should do as little as possible beyond accepting, relaying, protecting, and accounting for mail flow. The goal is a narrower trust surface for operators who do not want the mail transfer tier to become a general-purpose message processing system.

Positioning

The intended audience for the first release of this site is mail operators:

• self-hosters running their own mail stack
• infrastructure teams operating relay or gateway tiers
• security-conscious deployments that want tighter separation of duties

What the name implies

The phrase zero-knowledge should be read as product positioning, not as a blanket guarantee about every deployment shape.

The final implementation docs still need to define:

• what data zsmtp must hold in memory to relay mail
• what metadata is logged, queued, or exposed for operations
• which parts of the system are encrypted at rest or in transit
• what trust assumptions remain for administrators and downstream relays

Current state

This site is intentionally conservative.

• it uses the product description that exists today
• it avoids publishing speculative SMTP workflows
• it leaves space for verified install, config, and operational material to land next