Email Preflight
REMOTE · EMAIL-PREFLIGHT-MCP.ONRENDER.COM
x402 v2 payment requests; relays compatible clients' signed payments to the existing product API.
Available components
Last scanned (21 hours ago)
Scores higher than 4% of remote servers
Reachable. Last reached 18 Oct 2026.
Category Finance and Payments
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. How we score → Why this is hard to score →
Endpoint Security46
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 429, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability0
- Transport check failed: declared streamable-http, but the endpoint returned HTTP 503. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability0
- Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Tool Safety0
- Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Capabilities0
- Capabilities not yet verified: we couldn't read the endpoint's capabilities.Unverified
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.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 18 Oct 26 −51
- Endpoint reachability: reachable → not serving MCP ▼ security
- Stability: 0.53 → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- HTTPS: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. security
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- First check of Schema quality: unverified functional
- 17 Oct 26 −4
- 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. security
- Tool coverage: 100% → 33% ▼ functional
- 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” functional
- 16 Oct 26 +1
- Tool “email_preflight” rewrote its description, which is the text the model reads security
- Schema quality: 163 → 191 ▼ functional
- Server version: 0.2.0 → 0.3.0 functional
- 14 Oct 26 +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.
- 12 Oct 26 +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.
- 10 Oct 26 +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.
- 7 Oct 26 +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.
- 3 Oct 26 +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.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 18 Oct 2026 · Probed https://email-preflight-mcp.onrender.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=onrender.com | CN=WE1,O=Google Trust Services,C=US | 21 Sept 2026 | 20 Dec 2026 | ECDSA 256 | ECDSA-SHA256 | 6eb1e3fe7d0631ea1337bfa4a321c137 |
| SANs: onrender.com, *.onrender.com | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of email-preflight-mcp.onrender.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| onrender.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Inconclusive
We could not reach the endpoint well enough to judge its authorisation posture.
| Result | Inconclusive |
|---|---|
| HTTP status | 503 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://email-preflight-mcp.onrender.com/mcp | HTTP error | 503 | |
| http (plaintext) | http://email-preflight-mcp.onrender.com/mcp | Inconclusive | 429 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
email_check_mini Email Check Mini ~92
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.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | – |
No output schema declared.
No examples provided.
email_preflight Email Preflight ~191
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.
| Name | Type | Req | Description |
|---|---|---|---|
| string | yes | Email address to check. |
No output schema declared.
No examples provided.
url_preflight URL Preflight ~92
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.
| Name | Type | Req | Description |
|---|---|---|---|
| url | string | yes | – |
No output schema declared.
No examples provided.
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.
remote · email-preflight-mcp.onrender.com
claude mcp add --transport http tasuyoapp-ctrl-email-preflight 'https://email-preflight-mcp.onrender.com/mcp'
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.