Email deliverability tools inside Claude, ChatGPT and Cursor.

Connect it

{
  "mcpServers": {
    "pipefire": { "url": "https://pipefire.ai/mcp" }
  }
}

Then just ask, for example: “Check whether acme.com is set up properly to send email”, “Why did this email go to spam?” with the headers pasted in, or “Score this cold email and fix the subject line”.

The sixteen tools

• check_domain_email_setup MX, SPF, DKIM and DMARC in one go, each with pass, warn or fail and the fix.
• check_dmarc The DMARC record, its policy, and whether the domain can be impersonated.
• check_spf SPF validity, the 10-lookup limit, and the all mechanism.
• check_dkim The DKIM key, trying Google Workspace, Microsoft 365 and common selectors.
• check_mx Mail servers and which provider handles the email.
• check_bimi BIMI (logo in the inbox) and whether DMARC is strict enough for it.
• check_mta_sts The MTA-STS policy that forces encrypted delivery.
• check_blacklists A domain's sending IPs, or one IPv4 address, on Spamhaus, Barracuda, SpamCop and more.
• analyze_email_headers SPF, DKIM and DMARC results, alignment and delivery delays from raw headers.
• check_cold_email A cold email scored out of 10 for length, reading level, the ask and spam wording.
• test_subject_line A subject line scored out of 10, with fixes.
• suggest_sending_domains Lookalike sending domains for cold email, with live .com and .net availability.
• guess_email_addresses Likely address formats for a person at a company.
• generate_spf_record A valid SPF record from the services a domain sends with.
• generate_dmarc_record A DMARC record from a policy and report addresses.
• generate_dkim_record A DKIM public key formatted as the TXT record to publish.

They run the same code as the free tools on this site, so an answer in your assistant matches the answer on the page. Nothing costs per use, so nothing needs an account.