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Evidence for your next connection.

Independent measurements of remote MCP servers. Every observation has a timestamp.

Read-only probes

MCP server · Communication & messaging

MailX Email Deliverability

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

Checks passed
12 / 22

2 failed · 8 not measured

Median response
1442 ms

Median of successful probes over 7 days

30-day uptime
Not measured

Share of countable probes over 30 days, including daily rollups. Auth challenges are excluded.

Discovered tools
17

Tool definitions returned by this server

Independent monitoring

Health & checks

Status history

Responded

The server completed its last measured handshake. This is an observation, not a guarantee.

Last checked
Check summary by test group
Test areaPassedFailedUnmeasured
ConnectionCan a client connect and discover tools?
500
Reliability & speedDoes it respond consistently and quickly?
004
Access & authenticationWhat is required to use this server?
102
Tool qualityAre the tool definitions usable by an agent?
400
Publisher identityCan the publisher be traced to its source?
222

Unmeasured means there is not enough evidence to decide. How these checks work

Inspect individual checks 22 recorded

Core

  • Pass
    Reachable

    Latest probe returned HTTP 200 in 1442 ms.

  • Pass
    Valid handshake

    protocolVersion 2025-11-25, serverInfo.name mailx-deliverability.

  • Pass
    Lists tools

    tools/list returned 17 tools.

  • Pass
    Current protocol

    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.

Discovered

Recent measurements

Probe history

View status
Latest stored probes. Raw probe rows are kept for 14 days.
CheckedResultResponseTools
Connected1442 ms17