MAILTYPE — Email Domain Capability Intelligence
RemoteAbout MAILTYPE — Email Domain Capability Intelligence
MAILTYPE is a REST and MCP API for applications that need objective, domain-level email infrastructure checks. It reports DNS-based evidence and does not probe SMTP servers or claim that an individual mailbox exists.
Key features
- 01Domain existence and mail-receiving capability
- 02MX records and mail provider
- 03Disposable-domain evidence
- 04SPF, DMARC, and MTA-STS checks
- 05Confidence, evidence, and check time
Use cases
- 01Screen email domains before accepting addresses
- 02Identify disposable domains during registration
- 03Check mail infrastructure before routing messages
MCP support
Exposes the `inspect_mail_domain` tool to MCP clients at `https://mailtype-api.onrender.com/mcp`. It returns domain-level infrastructure evidence and does not verify individual mailbox existence.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://mailtype-api.onrender.com/mcpclaude mcp add --transport http gsterlingpress-mailtype https://mailtype-api.onrender.com/mcp{"mcpServers":{"gsterlingpress-mailtype":{"type":"http","url":"https://mailtype-api.onrender.com/mcp"}}}Open in Cursor{"servers":{"gsterlingpress-mailtype":{"type":"http","url":"https://mailtype-api.onrender.com/mcp"}}}Open in VS Code{"mcpServers":{"gsterlingpress-mailtype":{"type":"http","url":"https://mailtype-api.onrender.com/mcp"}}}{"mcpServers":{"gsterlingpress-mailtype":{"serverUrl":"https://mailtype-api.onrender.com/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
https://mailtype-api.onrender.com/mcpAuth requiredTools
Details
From the project READMEMAILTYPE
Email/domain → objective mail capability intelligence.
MAILTYPE is a tiny REST + MCP API for applications that need fast, objective domain-level email infrastructure answers before accepting, storing, routing, or acting on an email address.
Live API: https://mailtype-api.onrender.com/docs
OpenAPI: https://mailtype-api.onrender.com/openapi.json
Playground: https://mailtype-api.onrender.com/play?q=gmail.com
MCP endpoint: https://mailtype-api.onrender.com/mcp
What it returns
DOMAIN_EXISTSCAN_RECEIVE_MAIL- MX records and provider
- disposable-domain evidence
- SPF
- DMARC
- MTA-STS
- confidence, evidence, and
checked_at
Why MAILTYPE
MAILTYPE deliberately does not perform SMTP probing or claim that an individual mailbox exists. It answers the cheaper, objective domain-level questions that software often needs first. UNKNOWN is a valid answer whenever the evidence is insufficient.
REST
curl -H "X-API-Key: YOUR_KEY" \
https://mailtype-api.onrender.com/v1/domain/gmail.com
curl -H "X-API-Key: YOUR_KEY" \
https://mailtype-api.onrender.com/v1/email/[email protected]
MCP
Endpoint: POST https://mailtype-api.onrender.com/mcp
Tool: inspect_mail_domain
Input:
{"input":"gmail.com"}
Public discovery endpoints
- Docs: https://mailtype-api.onrender.com/docs
- Playground: https://mailtype-api.onrender.com/play?q=gmail.com
- OpenAPI 3.1: https://mailtype-api.onrender.com/openapi.json
- Sources and methodology: https://mailtype-api.onrender.com/sources
- Health: https://mailtype-api.onrender.com/health
Data and standards
MAILTYPE uses DNS evidence plus a maintained legally reusable disposable-domain dataset. The API exposes its methodology and source disclosure publicly. Relevant standards include RFC 5321, RFC 7505 (Null MX), RFC 7208 (SPF), RFC 7489 (DMARC), and RFC 8461 (MTA-STS).
Hard boundary
MAILTYPE does not verify that a mailbox exists, connect to recipient SMTP servers, send email, infer deliverability from opaque scores, or claim CAN_RECEIVE_MAIL=YES without explicit MX evidence. If a domain exists but explicit MX evidence is insufficient, MAILTYPE returns UNKNOWN.
Stranger Verification Standard
Our own tests, health probes, validators, uptime traffic, and known internal callers do not count as adoption. A tool call alone does not automatically become a verified stranger; outside calls remain unverified until evidence supports credible real use.
Keywords
email API · domain API · MX lookup API · disposable email domain API · SPF API · DMARC API · MTA-STS API · email infrastructure · email validation preflight · MCP server · developer API
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