MailX Email Deliverability

com.themailxPublished by themailx.comOfficial publisherv1.0.0Updated Oct 24, 2026

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

VerifiedStreamable HTTPWeb executableCommunication & CollaborationSecurity & Monitoring

Overview

AI-generated overview

Remote MCP server that lets an assistant audit a domain's email deliverability — SPF, DKIM, DMARC, BIMI, blacklists, MX and DNS — and generate DNS records.

What you can do
Run a full deliverability audit of a domain, or check SPF, DKIM, DMARC and BIMI records individually with pass, warning or fail results and fix suggestions, including automatic DKIM selector discovery and blacklist checks against major DNS blocklists. Generate ready-to-publish SPF and DMARC records, without publishing them. Look up DNS records: MX with priorities, TXT, CNAME, PTR reverse DNS, or all record types in one view. Find outgoing SMTP and incoming IMAP server settings for providers such as Gmail, Outlook, Microsoft 365, Zoho, Amazon SES and SendGrid. Test SMTP and IMAP logins for a mailbox the user controls, optionally sending one test email.
When to use it
Useful when diagnosing why email lands in spam, setting up or validating a sending domain's authentication records, checking whether a domain is blacklisted, or looking up mail server settings and DNS records for a provider.
Requirements
A remote streamable HTTP endpoint at the provider's site; no package, environment variable or header is declared. The server performs live DNS and mail-server lookups, so network access is needed. SMTP and IMAP tests require credentials for a mailbox the user controls.
Before you install
The SMTP and IMAP check tools take mail account credentials; the server states they are not stored, but they are still sent to a third-party service. The SMTP check can send a real test email when both sender and recipient addresses are given. Generated SPF and DMARC records are not published — the user must publish them. Domain and DNS queries are sent to the provider.

Installation

In SourceWeft

  1. Open MailX Email Deliverability in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/com.themailx%2Femail-deliverability/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

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

Tools

17

audit_domain

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.

Parametersdomain_namerequireddkim_selector

spf_check

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.

Parametersdomain_namerequired

dkim_check

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.

Parametersdomain_namerequireddkim_selector

dmarc_check

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.

Parametersdomain_namerequired

bimi_check

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.

Parametersdomain_namerequired

dmarc_generate

DMARC Generator

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

Parametersemailrequireddomain_namerequireddmarc_policyrequired

spf_generate

SPF Generator

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.

Parametersproviderrequireddomain_namerequiredhard_fail_booleanrequired

smtp_check

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.

Parametershostrequiredportrequiredpasswordrequiredto_emailusernamerequiredencryptionrequiredfrom_email

imap_check

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.

Parameterspasswordrequiredusernamerequiredimap_hostrequiredimap_portrequiredimap_encryptionrequired

smtp_finder

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.

Parametersprovider_namerequired

imap_finder

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.

Parametersimap_provider_namerequired

blacklist_check

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.

Parametersdomain_namerequired

mx_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.

Parametersdomain_namerequired

txt_lookup

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.

Parametersdomain_namerequired

cname_lookup

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.

Parametersdomain_namerequired

ptr_lookup

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.

Parametersip_addressrequired

dns_lookup

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.

Parametersdomain_namerequired

Version history

1
  1. v1.0.0LatestSep 16, 2026

Score

83% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.