SpamFixer Email Deliverability Check

com.spamfixerPublished by spamfixer.comOfficial publisherv1.0.0Updated Oct 29, 2026

Why do a domain's emails go to spam? Checks SPF, DKIM, DMARC, MX and blocklists. Free, no login.

VerifiedStreamable HTTPWeb executableCommunication & CollaborationSecurity & Monitoring

Overview

AI-generated overview

Remote MCP server that checks a domain's public DNS records and blocklist status to explain why its email may land in spam.

What you can do
  • Check a domain's email authentication setup: SPF, DKIM (common selectors), DMARC and MX records.
  • Check whether the domain's mail servers appear on major blocklists.
  • Get a 0-100 deliverability score with plain-English issues ordered worst first.
When to use it
Useful when someone asks why their emails go to spam or junk, or whether a domain's SPF, DKIM and DMARC are configured correctly. It works for any domain without an account.
Requirements
A remote endpoint at spamfixer.com over streamable HTTP; no account, API key or environment variables are declared. The server needs outbound access to public DNS and blocklist lookups on its side.
Before you install
Read-only: it changes nothing and sends no email. DKIM results depend on common selectors, so a missing key may be a false negative. Queries reveal the domain being investigated to the remote service.

Installation

In SourceWeft

  1. Open SpamFixer Email Deliverability Check in the dashboard and add it to a workspace.
  2. 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/com.spamfixer%2Femail-deliverability-check/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": {
    "spamfixer-email-deliverability-check": {
      "type": "http",
      "url": "https://spamfixer.com/mcp"
    }
  }
}

Tools

1

check_email_deliverability

Check email deliverability

Check why emails from a domain might land in spam. Looks up the domain's public DNS: SPF, DKIM (common selectors), DMARC, MX, and whether its mail servers are on major blocklists. Returns a 0-100 score and plain-English issues, worst first. Read-only: it changes nothing and sends no email. DKIM keys on custom selectors can't be found from outside, so "DKIM not found" is only a hint. Free email providers (gmail.com etc.) aren't checked. Args: domain: The domain that sends the email, e.g. "joesplumbing.com". A website URL or an email address also works; the domain is taken from it.

Parametersdomainrequired

Version history

1
  1. v1.0.0LatestOct 29, 2026

Score

72% 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 listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts

    Publish an icon in the registry entry.

  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.