MailX Email Deliverability

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

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

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "MailX Email Deliverability": {
      "url": "https://themailx.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (17)

• audit_domain read-only

  Use this when the user asks why their emails go to spam or wants a full deliverability check of a domain. Runs SPF, DKIM (finds the selector on its own), DMARC, blacklist and MX checks in one call and returns pass, warning or fail for each, an overall result, and the fixes to apply in priority order with help links. Takes about 10 seconds. mailX never changes DNS.

  Parameters:

  • domain_name (required) — string — The domain to audit, e.g. example.com
  • dkim_selector — string — The DKIM selector, e.g. google (Google Workspace), selector1 or selector2 (Microsoft 365). Optional: omit it to try common selectors.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• spf_check read-only

  Use this when the user asks whether a domain's SPF record is valid, which servers may send email for a domain, or why SPF fails. Returns the live SPF record, a pass/fail status and a fix suggestion.

  Parameters:

  • domain_name (required) — string — The domain to check SPF records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• dkim_check read-only

  Use this when the user wants to verify DKIM for a domain. Pass the DKIM selector if known (for example google for Google Workspace, selector1 or selector2 for Microsoft 365). If the selector is unknown, omit it: mailX then tries common selectors and returns the ones it finds. Returns the published key and its status. A miss on common selectors does not prove DKIM is absent.

  Parameters:

  • domain_name (required) — string — The domain to check DKIM records for, e.g. example.com
  • dkim_selector — string — The DKIM selector, e.g. google (Google Workspace), selector1 or selector2 (Microsoft 365). Optional: omit it to try common selectors.

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• dmarc_check read-only

  Use this when the user asks about DMARC, spoofing protection, or what happens to emails that fail authentication. Returns the live DMARC record, its policy and a fix suggestion.

  Parameters:

  • domain_name (required) — string — The domain to check DMARC records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• bimi_check read-only

  Use this when the user asks about BIMI or showing a brand logo next to their emails in inboxes. Returns the live BIMI record, the logo URL it declares, and a fix suggestion.

  Parameters:

  • domain_name (required) — string — The domain to check BIMI records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• dmarc_generate read-only

  Use this when the user needs a DMARC record. Returns the record name, value and type ready to publish. mailX does not publish it.

  Parameters:

  • domain_name (required) — string — The domain to generate a DMARC record for, e.g. example.com
  • email (required) — string — The email address to receive DMARC aggregate reports, e.g. [email protected]
  • dmarc_policy (required) — string — The DMARC policy: none (monitor only), quarantine (mark as spam), or reject (block entirely)

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• spf_generate read-only

  Use this when the user needs a new SPF record for their email provider. Returns a TXT record ready to publish, or explains what to set up instead when the provider does not need a root SPF include. mailX does not publish it.

  Parameters:

  • domain_name (required) — string — The domain to generate an SPF record for, e.g. example.com
  • provider (required) — string — Email provider identifier. Google Workspace or Gmail = google. Microsoft 365, Office 365 or Outlook = microsoft. Amazon SES = amazon-ses. Common provider names are also accepted.
  • hard_fail_boolean (required) — boolean — If true, uses strict -all policy (reject unauthorized senders). If false, uses soft ~all (mark but deliver).

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• smtp_check

  Use this only when the user explicitly asks to test an SMTP login for a mail account they control and provides its credentials. Connects to the SMTP server and reports whether connection, encryption and authentication succeed. If from_email and to_email are both given, it also sends one test email. Credentials are not stored.

  Parameters:

  • host (required) — string — The SMTP server hostname, e.g. smtp.gmail.com
  • port (required) — integer — The SMTP port number, e.g. 587 for TLS, 465 for SSL, 25 for unencrypted
  • username (required) — string — The SMTP username for authentication
  • password (required) — string — The SMTP password or app-specific password
  • encryption (required) — string — The encryption protocol: ssl, tls, or none
  • to_email — string — Optional recipient email address for sending a test email
  • from_email — string — Optional sender email address for sending a test email

  Hints: read-only no · destructive no · idempotent no · open-world yes

• imap_check

  Use this only when the user explicitly asks to test an IMAP login for a mailbox they control and provides its credentials. Connects to the IMAP server and reports whether connection, encryption and authentication succeed. Credentials are not stored.

  Parameters:

  • imap_host (required) — string — The IMAP server hostname, e.g. imap.gmail.com
  • imap_port (required) — integer — The IMAP port number, e.g. 993 for SSL, 143 for unencrypted
  • username (required) — string — The IMAP username for authentication
  • password (required) — string — The IMAP password or app-specific password
  • imap_encryption (required) — string — The encryption protocol: ssl, tls, or none

  Hints: read-only no · destructive no · idempotent yes · open-world yes

• smtp_finder read-only

  Use this when the user needs the outgoing mail (SMTP) server settings for an email provider or sending service, such as Gmail, Outlook, Microsoft 365, Zoho, Amazon SES or SendGrid. Returns the host, ports with encryption, what to use to log in, and the provider's setup guide. Never asks for the user's credentials.

  Parameters:

  • provider_name (required) — string — The email provider name to look up, e.g. gmail, sendgrid, mailgun, outlook

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• imap_finder read-only

  Use this when the user needs the incoming mail (IMAP) server settings for an email provider, such as Gmail, Outlook, Yahoo, iCloud or Zoho. Returns the host, ports with encryption and the provider's setup guide. Never asks for the user's credentials.

  Parameters:

  • imap_provider_name (required) — string — The email provider name to look up, e.g. gmail, outlook, yahoo

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• blacklist_check read-only

  Use this when the user suspects their domain is blacklisted or blocked. Checks the domain against major DNS blocklists and returns the result for each list.

  Parameters:

  • domain_name (required) — string — The domain name or IP address to check against blacklists, e.g. example.com or 1.2.3.4

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• mx_lookup read-only

  Use this when the user wants to know which mail servers receive email for a domain. Returns the domain's live MX records with their priorities.

  Parameters:

  • domain_name (required) — string — The domain to look up MX records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• txt_lookup read-only

  Use this when the user wants to see a domain's TXT records, for example to find verification tokens or check what SPF or other policies are published. Returns all live TXT records.

  Parameters:

  • domain_name (required) — string — The domain to look up TXT records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• cname_lookup read-only

  Use this when the user wants to know whether a hostname is an alias of another one, for example to verify DKIM or tracking CNAMEs. Returns the live CNAME target.

  Parameters:

  • domain_name (required) — string — The domain to look up CNAME records for, e.g. www.example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• ptr_lookup read-only

  Use this when the user wants the reverse DNS (PTR) of an IP address, for example to check a sending server's reverse DNS. Returns the hostname the IP resolves to.

  Parameters:

  • ip_address (required) — string — The IP address to look up, e.g. 8.8.8.8 or 142.250.80.46

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

• dns_lookup read-only

  Use this when the user wants every DNS record for a domain in one view (A, AAAA, CNAME, MX, NS, TXT, SOA). Returns the live records grouped by type.

  Parameters:

  • domain_name (required) — string — The domain to look up all DNS records for, e.g. example.com

  Hints: read-only yes · destructive no · idempotent yes · open-world yes

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