MailX Email Deliverability MCP Server

by themailx Your server? Claim it

answering

MailX Email Deliverability is answering right now. Last checked 10 min ago. It exposes 17 tools.

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

Uptime history 91 days of history

91 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

495 ms

Response time

average over 24h

open, no key

Access

streamable-http

What changed 19

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 12 October 2026. No other catalogue keeps this.

14 Oct a tool appeared audit_domain

12 Oct 16 tool descriptions were rewritten bimi_check, blacklist_check, cname_lookup and 13 more

12 Oct 2 tools changed the parameters they ask for dkim_check, spf_generate

Nothing serious here today

Today is the operative word: we check MailX Email Deliverability every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 10 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add email-deliverability --transport http https://themailx.com/mcp

Settings → Connectors → Add custom connector, then paste this address

https://themailx.com/mcp

~/.codex/config.toml

[mcp_servers.email-deliverability]
url = "https://themailx.com/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "email-deliverability": {
      "url": "https://themailx.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "email-deliverability": {
      "type": "http",
      "url": "https://themailx.com/mcp"
    }
  }
}

Available tools 17

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

dmarc

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.

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.

imap

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.

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.

smtp

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.

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.

spf

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.

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.

audit

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.

bimi

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.

blacklist

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.

cname

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.

dkim

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.

dns

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.

lookup

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.

ptr

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.

txt

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.

Endpoints

URL	Transport	State	Latency	Checked
https://themailx.com/mcp	streamable-http	answering	633 ms	10 min ago

Alternatives to MailX Email Deliverability

same job, measured the same way

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Check SPF, DKIM, DMARC, blocklists, reverse DNS and email headers against Gmail/Yahoo sender rules.

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SpamFixer Email Deliverability Check

by spamfixer

Why do a domain's emails go to spam? Checks SPF, DKIM, DMARC, MX and blocklists. Free, no login.

1 tools answering

Pipefire email deliverability tools

by pipefire

Free email deliverability tools: SPF, DKIM, DMARC, blacklist and header checks, cold email scoring.

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Inbox Check — Email Deliverability Test

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Email inbox placement tests across Gmail, Outlook, Yahoo, Mail.ru, Yandex (SPF/DKIM/DMARC).

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MCP Domain Deliverability Checker

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Audit a domain email deliverability via Apify: SPF, DKIM, DMARC, MX, blacklist, catch-all, age.

74 installs/wk local only

MailX Email Deliverability — questions

Answers built from our own checks of this server.

What can MailX Email Deliverability do?

It exposes 17 tools, read directly from the server on our last check. Among them: audit_domain, bimi_check, blacklist_check, cname_lookup, dkim_check, dmarc_check and 11 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

What is MailX Email Deliverability mostly used for?

Its tools cluster around dmarc, imap and smtp. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is MailX Email Deliverability working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 495 ms. The bar chart above shows every period we have measured.

How do I connect MailX Email Deliverability?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does MailX Email Deliverability need an API key?

No. MailX Email Deliverability completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 17 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is MailX Email Deliverability?

It answers our handshake in 495 ms on average, which is faster than 24% of all working MCP servers we measure. That is on the slow side — worth knowing if the tool sits inside an interactive loop. The comparison comes from our own checks across the whole registry, every 15 minutes.