Build on ISET.email.

One platform, three doors: a transactional send API for integrators, the mailbox web API for humans, and a native MCP server for AI agents. Every message leaves ML-DSA-65-signed; every mailbox is ML-KEM-768-sealed.

Send your first email

curl -X POST https://iset.email/v1/emails \
  -H "Authorization: Bearer isk_…" -H "content-type: application/json" \
  -d '{"from":"hi@yourdomain.com","to":"user@example.com","subject":"Signed","html":"<p>sealed &amp; signed</p>"}'

Mint a domain key in the console (Connect a domain → keys). The from address must live on the key's domain. Accepted mail returns an id and emits signed lifecycle envelopes.

Provision mailboxes

curl -X POST https://iset.email/v1/mailboxes \
  -H "Authorization: Bearer isk_…" -H "content-type: application/json" \
  -d '{"address":"alice@yourdomain.com","kind":"agent"}'

Wire in an AI agent (MCP)

Native Model Context Protocol — list, search, read, ask-inbox, draft, send. Generate a scoped key in Settings → Connect AI agents (read-only or full), or connect with zero configuration via OAuth discovery.

{
  "mcpServers": { "iset-email": {
    "command": "npx", "args": ["-y", "mcp-remote", "https://iset.email/mcp",
      "--header", "Authorization: Bearer YOUR_KEY"] } }
}

Endpoint: https://iset.email/mcp · JSON-RPC 2.0 · Streamable HTTP · stateless

Export your data

Signed in: GET https://iset.email/v2/export streams every message as NDJSON. End-to-end-sealed mail exports as ciphertext — readable only with your key. That's the point.

Contract

Concern	Behavior
Errors	{ "error": { "code": "…", "message": "…" } } with correct HTTP status (401 · 403 · 404 · 409 · 422 · 429 · 5xx)
Rate limits	Per-tier daily sends (100 / 300 / 500; Verified ID +50%) → 429 + Retry-After
Auth scopes	isk_ one domain · mcp_ read|full, revocable · oat_ OAuth, 30-day, refresh-rotated, revocable
Signed mail	X-Sovereign-Sig (ML-DSA-65, FIPS 204) + ISP envelope codes on every state change
E2E line	Sealed mail is never decrypted for agents — a statement is returned instead of plaintext

Reference