Negotiated 2025-11-25. The bar is 2025-06-18 or newer.
Pass
HTTPS
The endpoint URL is https.
Performance
Not measured
Fast (p50)
Median latency 1442 ms over 1 samples in 7 days. The bar is 1000 ms. Need at least 5 samples.
Not measured
Consistent (p95)
95th percentile 1442 ms over 1 samples in 7 days. The bar is 3000 ms. Need at least 20 samples.
Not measured
Reliable (uptime)
1 of 1 attempts returned a tool list in 30 days (100%). The bar is 99%. Need at least 30 samples.
Not measured
Stable tool list
Fewer than two successful probes in 30 days, so tool-list stability is not measured.
Access
Pass
Open access
tools/list succeeded with no credential, and the record declares none.
Not measured
Standard auth
Auth is not required, so the OAuth metadata check does not apply.
Not measured
Free tier cited
No publisher quote has been checked.
Tools
Pass
Tools described
Every tool description is at least 20 characters.
Pass
Valid input schemas
Every inputSchema is a JSON Schema object.
Pass
Parameters documented
33 of 33 parameters have a description (100%). The bar is 80%.
Pass
Safety hints
Every tool sets readOnlyHint or destructiveHint.
Publisher
Pass
Verified namespace
Listed in the Official MCP Registry.
Pass
Website matches publisher
The website host matches the reverse-domain namespace.
Fail
Source repo linked
No repository URL is on file.
Not measured
Repo owner matches
This namespace is not an io.github login, so the owner comparison does not apply.
Fail
Recently updated
Updated 2026-04-17T21:04:43.17105Z, which is older than 180 days.
Not measured
Open-source licence
No GitHub repository to ask about a licence.
Start using MailX Email Deliverability
Connect to this server
Choose your client, copy the configuration, then enable the server in your client’s MCP settings.
Run this command in your terminal, then restart Claude Code.
Claude Code
claude mcp add --transport http mailx-email-deliverability https://themailx.com/mcp
Capabilities
Tools 17
audit_domain
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.
Discovered bimi_check
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.
Discovered blacklist_check
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.
Discovered cname_lookup
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.
Discovered dkim_check
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.
Discovered dmarc_check
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.
Discovered dmarc_generate
Use this when the user needs a DMARC record. Returns the record name, value and type ready to publish. mailX does not publish it.
Discovered dns_lookup
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.
Discovered 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.
Discovered imap_finder
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.
Discovered mx_lookup
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.
Discovered ptr_lookup
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.
Discovered 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.
Discovered smtp_finder
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.
Discovered spf_check
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.
Discovered spf_generate
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.
Discovered txt_lookup
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.