SpamFixer

Check your email deliverability from Meta Muse or Claude

The SpamFixer connector lets your AI assistant answer "why are my emails going to spam?" for any domain. It checks the domain's public email setup and explains each problem in plain English, worst first, with a score out of 100. It's free, needs no account or sign-in, and only reads public DNS.

Add it to your assistant

Connector address: https://spamfixer.com/mcp

  • Meta Muse: open Settings → Connectors, choose to add a custom connector, and paste the address above.
  • Claude: open Settings → Connectors → Add custom connector, and paste the address above.
  • Other MCP clients: it's a remote MCP server over Streamable HTTP with no authentication.

What to ask

  • "Why are my emails going to spam? My website is joesplumbing.com"
  • "Is the email for my domain set up correctly?"
  • "Do I have DMARC set up on mybakery.com?"

You can give a domain, a website address or an email address. If you give an address at Gmail, Outlook or another free provider, the connector explains that the provider manages that domain and asks for your business domain instead.

What it checks

  • SPF: whether the record exists, is unique, stays within the 10-DNS-lookup limit and ends with a real policy.
  • DKIM: whether a signing key is published on common selectors.
  • DMARC: whether the record exists, is valid, enforces a policy and has a reporting address.
  • MX: whether the domain can receive email.
  • Blocklists: whether the domain's mail servers are on major spam blocklists.

DKIM keys on custom selectors can't be guessed from DNS, so "DKIM not found" is a low-severity note, not proof that emails are unsigned.

Tool reference

check_email_deliverability(domain) is the only tool. It is read-only: it never changes anything and never sends email. It returns a plain-text report: the score, each record's status, and the issues with their severity (high, medium or low).

Requests are rate-limited per client. See the privacy policy for what we record and the terms for use of the service.

Want it fixed?

If the check finds a serious problem, SpamFixer can fix it for you: a flat $199, and you don't pay if we can't fix it. See how it works or email hello@spamfixer.com.