MailX Email Deliverability

Check SPF/DKIM/DMARC/BIMI, blacklists, SMTP/IMAP; DNS lookups; generate email DNS records.

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What it can do

    What data it sees

    Do you need an account

    No: the server works without sign-in

    Check SPF/DKIM/DMARC/BIMI, blacklists, SMTP/IMAP; DNS lookups; generate email DNS records.

    How to connect

    How to connect MailX Email Deliverability to Claude

    The server address to paste into Claude settings:

    https://themailx.com/mcp

    1. Open Claude (claude.ai or the desktop app).
    2. Go to Settings → Connectors.
    3. Click Add custom connector.
    4. Paste the server address copied below into Remote MCP server URL and click Add.
    5. In a chat, click + → Connectors and switch the new connector on.

    Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

    Authorization

    After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

    How to connect MailX Email Deliverability to ChatGPT

    The server address to paste into ChatGPT settings:

    https://themailx.com/mcp

    1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
    2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
    3. Open Settings → Connectors and click Create.
    4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
    5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
    6. In a new chat open + → Apps/Connectors and enable the connector.

    OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

    Authorization

    On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

    How to connect MailX Email Deliverability to Cursor

    The server address to paste into Cursor settings:

    https://themailx.com/mcp

    Fastest: click Open in Cursor below and confirm the prompt.

    Manually:

    1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
    2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
    3. Save the file. The server appears in the MCP list; authorize it there if asked.

    Authorization

    If the service needs sign-in, an authorize button appears next to the server in the MCP list.

    Server tool list (16)

    Raw names from tools/list. Only developers need these.

    spf_checkCheck if a domain has a valid SPF (Sender Policy Framework) DNS record. SPF specifies which mail servers are authorized to send email on behalf of a domain.
    dkim_checkCheck if a domain has a valid DKIM (DomainKeys Identified Mail) DNS record for a given selector. DKIM allows the receiver to verify that an email was sent by the domain owner.
    dmarc_checkCheck if a domain has a valid DMARC (Domain-based Message Authentication, Reporting & Conformance) DNS record. DMARC tells receiving servers what to do with emails that fail SPF or DKIM checks.
    bimi_checkCheck if a domain has a valid BIMI (Brand Indicators for Message Identification) DNS record. BIMI allows brands to display their logo next to authenticated emails in supporting email clients.
    dmarc_generateGenerate a DMARC DNS record for a domain. Returns the record name, value, and type ready to be added to DNS.
    spf_generateGenerate an SPF DNS record for a domain based on the email provider being used. Returns the record name, value, and type ready to be added to DNS.
    smtp_checkTest an SMTP server connection by attempting to connect and authenticate. If from_email and to_email are provided, the tool may attempt to send a test email. Only provide these fields if you are authorized to send from the account and intentionally want to test full sending capability.
    imap_checkTest an IMAP server connection by attempting to connect and authenticate. Use this to verify email receiving configuration.
    smtp_finderLook up SMTP server settings (host, port, encryption) for a given email provider. Use this to find the correct SMTP configuration for services like Gmail, Outlook, SendGrid, etc.
    imap_finderLook up IMAP server settings (host, port, encryption) for a given email provider. Use this to find the correct IMAP configuration for services like Gmail, Outlook, Yahoo, etc.
    blacklist_checkCheck if a domain or IP address is listed in popular email blacklists (DNSBLs). Being blacklisted can severely impact email deliverability.
    mx_lookupLook up MX (Mail Exchanger) records for a domain. Returns the mail servers and their priorities.
    txt_lookupLook up all TXT records for a domain. TXT records contain SPF policies, domain verification tokens, DKIM keys, and other metadata.
    cname_lookupLook up CNAME (Canonical Name) records for a domain. Shows where a hostname aliases to.
    ptr_lookupReverse DNS lookup. Find the hostname associated with an IP address. A valid PTR record is important for email sending reputation.
    dns_lookupLook up all DNS records for a domain in one query. Returns A, AAAA, CNAME, MX, NS, TXT, and SOA records.