# Email Preflight (remote · email-preflight-mcp.onrender.com)

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

- Trust score: 18/100 (low)
- Change this week: −52
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-10-18

## Components

- remote · `email-preflight-mcp.onrender.com`: 18/100 (this document), [markdown](https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp.md), [page](https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp)

## Channel facts

- Endpoint: `https://email-preflight-mcp.onrender.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.3.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-10-18.

- **Endpoint Security**: 46/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 429, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but the endpoint returned HTTP 503.
- **Schema Quality & AI Usability**: 0/100
  - Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 0/100
  - Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Tool Safety**: 0/100
  - Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Capabilities**: 0/100
  - Capabilities not yet verified: we couldn't read the endpoint's capabilities.

**Unverified: 5 categories.** Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.

## Install

### How do I install the Email Preflight MCP server?

Email Preflight is a hosted endpoint at https://email-preflight-mcp.onrender.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http tasuyoapp-ctrl-email-preflight 'https://email-preflight-mcp.onrender.com/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "tasuyoapp-ctrl-email-preflight": {
      "url": "https://email-preflight-mcp.onrender.com/mcp"
    }
  }
}
```

### VS Code

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

### Codex

```toml
[mcp_servers.tasuyoapp-ctrl-email-preflight]
url = "https://email-preflight-mcp.onrender.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "tasuyoapp-ctrl-email-preflight": {
      "type": "remote",
      "url": "https://email-preflight-mcp.onrender.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add tasuyoapp-ctrl-email-preflight --url 'https://email-preflight-mcp.onrender.com/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  tasuyoapp-ctrl-email-preflight:
    url: "https://email-preflight-mcp.onrender.com/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "tasuyoapp-ctrl-email-preflight": {
      "Transport": "http",
      "Url": "https://email-preflight-mcp.onrender.com/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add tasuyoapp-ctrl-email-preflight -t streamable-http -u 'https://email-preflight-mcp.onrender.com/mcp'
```

### Other

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

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-10-18 (score 18, −51)

- [security regression] Endpoint reachability: reachable → not serving MCP
- [security regression] Stability: 0.53 → unverified
- [security regression] Tool safety: pass → unverified
- [security regression] HTTPS: pass → unverified
- [security regression] Transport: pass → fail
- [security] Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional] First check of Schema quality: unverified

### 2026-10-17 (score 69, −4)

- [security] Authorization: Authorisation not fully verified: no authorisation is required to call this server, and 3 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
- [functional regression] Tool coverage: 100% → 33%
- [functional improvement] Schema quality: 191 → 125
- [functional] Schema quality: excellent → good
- [functional] Server version: 0.3.0 → 0.5.0
- [functional] New tool “email_check_mini”
- [functional] New tool “url_preflight”

### 2026-10-16 (score 73, +1)

- [security] Tool “email_preflight” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 163 → 191
- [functional] Server version: 0.2.0 → 0.3.0

### 2026-10-14 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 40 to 43. That category is still filling its 30-day observation window: 12 days of observed history at the previous scan, 13 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-12 (score 71, +1)

No change was recorded against any check on this day. Stability & Change Management went from 30 to 37. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 11 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-10 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 30. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 9 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-07 (score 69, +2)

No change was recorded against any check on this day. Stability & Change Management went from 10 to 20. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-03 (score 67, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

## MCP tools (3)

### `email_preflight` (~191 tokens)

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.

Input parameters:

- `email` (string, required): Email address to check.

### `email_check_mini` (~92 tokens)

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.

Input parameters:

- `email` (string, required)

### `url_preflight` (~92 tokens)

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.

Input parameters:

- `url` (string, required)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp#diagnostics

## Score history

- 2026-10-18: 18
- 2026-10-17: 69
- 2026-10-16: 73
- 2026-10-15: 72
- 2026-10-14: 72
- 2026-10-13: 71
- 2026-10-12: 71
- 2026-10-10: 70
- 2026-10-07: 69
- 2026-10-04: 67
- 2026-10-03: 67
- 2026-10-02: 66
- 2026-10-01: 65

## Common questions

### What is the Email Preflight MCP server?

Email Preflight is an MCP server listed in the public MCP registry as io.github.tasuyoapp-ctrl/email-preflight. x402 v2 payment requests; relays compatible clients' signed payments to the existing product API. This page covers its hosted endpoint (https://email-preflight-mcp.onrender.com/mcp).

### Is the Email Preflight MCP server safe to use?

Email Preflight scores 18 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Email Preflight MCP server expose?

Email Preflight exposes 3 tools: email_preflight, email_check_mini, url_preflight. Their descriptions and schemas cost roughly 375 tokens of context every time the server is loaded.

### Does the Email Preflight MCP server require authentication?

Its publisher declares no required credentials for Email Preflight. We have not been able to confirm that against the live endpoint, and a server can require authorisation without declaring it here.

### Is the Email Preflight MCP server still maintained?

Email Preflight is still listed as active in the MCP registry. We last reached this channel on 18 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://email-preflight-mcp.onrender.com/mcp
- Changelog RSS feed: https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp.json
- HTML version of this page: https://verifymcp.io/servers/tasuyoapp-ctrl-email-preflight/email-preflight-mcp