MAILTYPE — Email Domain Capability Intelligence

io.github.GSterlingPressPublished by GitHub account GSterlingPressv1.0.2Updated Oct 27, 2026

Email-domain intelligence: MX capability, provider, disposable status, SPF, DMARC, and MTA-STS.

The publisher's own server: Physical Capability Cloud

VerifiedStreamable HTTPWeb executableDeveloper ToolsSecurity & Monitoring

Overview

AI-generated overview

Remote MCP server that answers domain-level email infrastructure questions: MX capability, provider, disposable status, SPF, DMARC and MTA-STS.

What you can do
  • Inspect a domain or email address for objective mail capability signals
  • Return whether the domain exists and whether it can receive mail, with MX records and provider
  • Report disposable-domain evidence, SPF, DMARC and MTA-STS findings
  • Return confidence, supporting evidence and a checked_at timestamp, with UNKNOWN when evidence is insufficient
When to use it
Useful as a preflight check before an application accepts, stores, routes or acts on an email address, or when an assistant needs quick domain-level mail infrastructure facts without SMTP probing.
Requirements
Remote streamable HTTP endpoint; no local runtime or package. Requires a MAILTYPE API key sent in the X-API-Key header. Network access to the hosted service.
Before you install
The API key is a secret sent in the X-API-Key header; keep it out of logs and shared configs. Queried domains and addresses go to a third-party hosted service. It does not verify that a specific mailbox exists, does not send email, and may return UNKNOWN rather than a definitive answer.

Installation

In SourceWeft

  1. Open MAILTYPE — Email Domain Capability Intelligence in the dashboard and add it to a workspace.
  2. Connect X-API-Key credentials. They are stored privately and never shown on public pages.
  3. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.GSterlingPress%2Fmailtype/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "mailtype-email-domain-capability-intelli": {
      "type": "http",
      "url": "https://mailtype-api.onrender.com/mcp",
      "headers": {
        "X-API-Key": "<YOUR_API_KEY>"
      }
    }
  }
}

README

MAILTYPE

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_EXISTS
  • CAN_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

bash
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:

json
{"input":"gmail.com"}

Public discovery endpoints

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

Source: README.md at commit 324105a

Tools

0
This server asks for a credential such as an API key, so SourceWeft could not read its tools without one and has not indexed them.

Version history

1
  1. v1.0.2LatestSep 16, 2026

Score

75% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.

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