# Email Preflight

> x402 v2 payment requests; relays compatible clients' signed payments to the existing product API.

- name: io.github.tasuyoapp-ctrl/email-preflight
- version: 0.3.0
- connection class: unknown (unknown)
- trust: 49/100 flags: no-repository, unreachable
- quality: 73/100 (needs work)
- owner: not claimed
- descriptor: https://api.protogrid.dev/v1/servers/io.github.tasuyoapp-ctrl%2Femail-preflight
- tools: https://api.protogrid.dev/v1/servers/io.github.tasuyoapp-ctrl%2Femail-preflight/tools

**Not classified yet.** The remote endpoints have not been probed successfully, or the listing has nothing to connect to.

## Connection (mcpServers)

```json
{
  "mcpServers": {
    "email-preflight": {
      "type": "http",
      "url": "https://email-preflight-mcp.onrender.com/mcp"
    }
  }
}
```


## Trust

- hygiene: 80
- liveness: 8
- freshness: 100
- provenance: 35
- drivers: -unreachable(3 failures) +updated-5d-ago -no-repository
- Derived from observable signals (official registry feed and our own credential-free probes); no code audit performed.

## Quality 73/100 (needs work)

### protocol: 88 (weight 25)

- pass `protocol.modern`: supports 2026-07-28 (server/discover)
- pass `protocol.stateless`: answers without a session
- pass `protocol.transport`: streamable HTTP
- warn `protocol.list_ttl`: tools/list declares ttlMs 0, so clients re-fetch it on every use

### authorization: n/a (weight 15)

- n/a `auth.prm`, `auth.as_metadata`, `auth.cimd`: no remote uses OAuth
- n/a `auth.secret_in_url`: no templated URL

### tool hygiene: 71 (weight 30)

- pass `tools.descriptions`: every tool has a description
- pass `tools.description_length`: descriptions are concise
- pass `tools.schemas`: every tool has an object input schema
- fail `tools.annotations`: no tool declares readOnlyHint or destructiveHint, so clients cannot tell safe calls from risky ones
- fail `tools.directory_hints`: no tool declares all four of readOnlyHint, destructiveHint, idempotentHint and openWorldHint; missing: email_check_mini (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); url_preflight (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); email_preflight (readOnlyHint, destructiveHint, idempotentHint, openWorldHint)
- pass `tools.token_cost`: about 491 tokens to load every tool
- pass `tools.api_dump`: tools are not a one-to-one API dump

### stability: 50 (weight 15)

- pass `stability.changes`: 4 tool changes in 30 days
- fail `stability.rug_pull`: 1 tools kept their name but changed most of their description in 30 days; review before trusting them

### dependencies: n/a (weight 15)

- n/a `deps.known_vulns`, `deps.mcp_sdk_version`, `deps.resolvable`: no npm or PyPI package

- tools: 3, about 491 tokens to load them all
- tool set hash: 05de3fd6760c237030e45be621445ecc
- tools last changed: 2026-10-16T10:15:57.364Z
- badge: [![protogrid quality](https://protogrid.dev/badge/io.github.tasuyoapp-ctrl/email-preflight.svg)](https://protogrid.dev/servers/io.github.tasuyoapp-ctrl/email-preflight)
- Checks run on what our credential-free, read-only probes observe; tools are never called and no code audit is performed.

### Tool changes

- 2026-10-16 `url_preflight` added
  - Inspect public HTTP/HTTPS URL response metadata through the existing safe URL API. $0.001 USDC on Base mainnet. Unpaid calls return x402 v2 requirements. A compatible client may repeat the identical url argument with its own signed PaymentPayload in params._meta["x402/payment"]. This bridge does not fetch that URL directly, sign payments, or settle independently.
- 2026-10-16 `email_check_mini` added
  - Check email syntax, MX and local domain classes with the existing API. $0.001 USDC on Base mainnet. MX does not prove mailbox existence. Unpaid calls return x402 v2 requirements for this request. A compatible client may repeat identical arguments with its own PaymentPayload in params._meta["x402/payment"]. The adapter does not sign or settle independently.
- 2026-10-16 `email_preflight` changed (description)
  - before: Use before sending or processing an email when you need current preflight facts about the address. For $0.001 USDC on Base mainnet, the existing Email Preflight API checks six facts: syntax validity, domain availability, MX availability, disposable-email detection, role-account detection, and free-provider detection. Example paid result shape: { email: "user@example.com", syntax: "valid", domain: "exists", mx: "found", disposable: "not_listed", role_based: "not_detected", free_provider: "not_detected" }. MX records do not prove that a mailbox exists. Unpaid requests return the original upstream HTTP 402 challenge. This adapter never signs or pays.
  - after: Use before sending or processing an email when you need current preflight facts about the address. For $0.001 USDC on Base mainnet, the existing Email Preflight API checks six facts: syntax validity, domain availability, MX availability, disposable-email detection, role-account detection, and free-provider detection. Example paid result shape: { email: "user@example.com", syntax: "valid", domain: "exists", mx: "found", disposable: "not_listed", role_based: "not_detected", free_provider: "not_detected" }. MX records do not prove that a mailbox exists. Unpaid requests return the original upstream HTTP 402 challenge. A compatible x402 client may retry with its own signed PaymentPayload in params._meta["x402/payment"]. This adapter never signs, owns a wallet, or settles independently.
- 2026-10-02 `email_preflight` changed (description) **meaning changed**
  - before: Connects to the existing Email Preflight API. Unpaid requests return the original upstream HTTP 402 body and PAYMENT-REQUIRED header. This adapter never signs or pays.
  - after: Use before sending or processing an email when you need current preflight facts about the address. For $0.001 USDC on Base mainnet, the existing Email Preflight API checks six facts: syntax validity, domain availability, MX availability, disposable-email detection, role-account detection, and free-provider detection. Example paid result shape: { email: "user@example.com", syntax: "valid", domain: "exists", mx: "found", disposable: "not_listed", role_based: "not_detected", free_provider: "not_detected" }. MX records do not prove that a mailbox exists. Unpaid requests return the original upstream HTTP 402 challenge. This adapter never signs or pays.

Full history: https://api.protogrid.dev/v1/servers/io.github.tasuyoapp-ctrl%2Femail-preflight/changes

## Remotes

- https://email-preflight-mcp.onrender.com/mcp (streamable-http, auth none, reachable false, uptime30d 0.9402985)

## Packages

_none_

## Tools (3)

- `email_check_mini`: Check email syntax, MX and local domain classes with the existing API. $0.001 USDC on Base mainnet. MX does not prove mailbox existence. Unpaid calls return x402 v2 requirements for this request. A compatible client may repeat identical arguments with its own PaymentPayload in params._meta["x402/payment"]. The adapter does not sign or settle independently.
- `email_preflight`: Use before sending or processing an email when you need current preflight facts about the address. For $0.001 USDC on Base mainnet, the existing Email Preflight API checks six facts: syntax validity, domain availability, MX availability, disposable-email detection, role-account detection, and free-provider detection. Example paid result shape: { email: "user@example.com", syntax: "valid", domain: "exists", mx: "found", disposable: "not_listed", role_based: "not_detected", free_provider: "not_detected" }. MX records do not prove that a mailbox exists. Unpaid requests return the original upstream HTTP 402 challenge. A compatible x402 client may retry with its own signed PaymentPayload in params._meta["x402/payment"]. This adapter never signs, owns a wallet, or settles independently.
- `url_preflight`: Inspect public HTTP/HTTPS URL response metadata through the existing safe URL API. $0.001 USDC on Base mainnet. Unpaid calls return x402 v2 requirements. A compatible client may repeat the identical url argument with its own signed PaymentPayload in params._meta["x402/payment"]. This bridge does not fetch that URL directly, sign payments, or settle independently.