MailX Email Deliverability
REMOTE · THEMAILX.COM
Check SPF/DKIM/DMARC/BIMI, blacklists, SMTP/IMAP; DNS lookups; generate email DNS records.
Available components
Last scanned (9 hours ago)
Scores higher than 96% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Communication
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security74
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability89
- 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).Pass
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 2009 tokens (~105/item across 19 items; 17 tools + 2 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management100
- No destabilizing schema changes in the last 30 days.Pass
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 17 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 19 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 15 Oct 26 0
- The server rewrote its instructions, which are the text every model session reads security
- Schema quality: pass → fail ▼ functional
- New tool “audit_domain” functional
- 12 Oct 26 +1
- The server rewrote its instructions, which are the text every model session reads security
- Tool “bimi_check” rewrote its description, which is the text the model reads security
- Tool “blacklist_check” rewrote its description, which is the text the model reads security
- Tool “cname_lookup” rewrote its description, which is the text the model reads security
- Tool “dkim_check” rewrote its description, which is the text the model reads security
- Tool “dmarc_check” rewrote its description, which is the text the model reads security
- Tool “dmarc_generate” rewrote its description, which is the text the model reads security
- Tool “dns_lookup” rewrote its description, which is the text the model reads security
- Tool “imap_check” rewrote its description, which is the text the model reads security
- Tool “imap_finder” rewrote its description, which is the text the model reads security
- Tool “mx_lookup” rewrote its description, which is the text the model reads security
- Tool “ptr_lookup” rewrote its description, which is the text the model reads security
- Tool “smtp_check” rewrote its description, which is the text the model reads security
- Tool “smtp_finder” rewrote its description, which is the text the model reads security
- Tool “spf_check” rewrote its description, which is the text the model reads security
- Tool “spf_generate” rewrote its description, which is the text the model reads security
- Tool “txt_lookup” rewrote its description, which is the text the model reads security
- Schema quality: 82 → 102 ▼ functional
- “dkim_check” reworded the description of “dkim_selector” cosmetic
- “spf_generate” reworded the description of “provider” cosmetic
- “dkim_check” made “dkim_selector” optional cosmetic
- 28 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 25 Aug 26 0
- Stability: 0.97 → pass security
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://themailx.com/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=themailx.com | CN=Amazon RSA 2048 M04,O=Amazon,C=US | 21 Aug 2026 | 6 Mar 2027 | RSA 2048 | SHA256-RSA | 38d3b48b2366bd2b2d2439d1db2f0f3 |
| SANs: themailx.com, *.themailx.com | ||||||
| CN=Amazon RSA 2048 M04,O=Amazon,C=US (CA) | CN=Amazon Root CA 1,O=Amazon,C=US | 23 Aug 2022 | 23 Aug 2030 | RSA 2048 | SHA256-RSA | 773124f2a952e3ed18a58bdb85d1bc0ce5f27 |
| CN=Amazon Root CA 1,O=Amazon,C=US (CA) | CN=Starfield Services Root Certificate Authority - G2,O=Starfield Technologies\, Inc.,L=Scottsdale,ST=Arizona,C=US | 25 May 2015 | 31 Dec 2037 | RSA 2048 | SHA256-RSA | 67f944a2a27cdf3fac2ae2b01f908eeb9c4c6 |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of themailx.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| themailx.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://themailx.com/mcp | Verified | 200 | |
| http (plaintext) | http://themailx.com/mcp | HTTPS enforced | 301 | https://themailx.com/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
audit_domain Audit Domain ~151
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.
| Name | Type | Req | Description |
|---|---|---|---|
| dkim_selector | string | – | The DKIM selector, e.g. google (Google Workspace), selector1 or selector2 (Microsoft 365). Optional: omit it to try common selectors. |
| domain_name | string | yes | The domain to audit, e.g. example.com |
No output schema declared.
No examples provided.
bimi_check BIMI Check ~71
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to check BIMI records for, e.g. example.com |
No output schema declared.
No examples provided.
blacklist_check Blacklist Check ~72
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain name or IP address to check against blacklists, e.g. example.com or 1.2.3.4 |
No output schema declared.
No examples provided.
cname_lookup CNAME Lookup ~69
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to look up CNAME records for, e.g. www.example.com |
No output schema declared.
No examples provided.
dkim_check DKIM Check ~153
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.
| Name | Type | Req | Description |
|---|---|---|---|
| dkim_selector | string | – | The DKIM selector, e.g. google (Google Workspace), selector1 or selector2 (Microsoft 365). Optional: omit it to try common selectors. |
| domain_name | string | yes | The domain to check DKIM records for, e.g. example.com |
No output schema declared.
No examples provided.
dmarc_check DMARC Check ~69
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to check DMARC records for, e.g. example.com |
No output schema declared.
No examples provided.
dmarc_generate DMARC Generator ~119
Use this when the user needs a DMARC record. Returns the record name, value and type ready to publish. mailX does not publish it.
| Name | Type | Req | Description |
|---|---|---|---|
| dmarc_policy | string | yes | The DMARC policy: none (monitor only), quarantine (mark as spam), or reject (block entirely) |
| domain_name | string | yes | The domain to generate a DMARC record for, e.g. example.com |
| string | yes | The email address to receive DMARC aggregate reports, e.g. dmarc@example.com |
No output schema declared.
No examples provided.
dns_lookup DNS Lookup ~72
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to look up all DNS records for, e.g. example.com |
No output schema declared.
No examples provided.
imap_check IMAP Check ~153
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.
| Name | Type | Req | Description |
|---|---|---|---|
| imap_encryption | string | yes | The encryption protocol: ssl, tls, or none |
| imap_host | string | yes | The IMAP server hostname, e.g. imap.gmail.com |
| imap_port | integer | yes | The IMAP port number, e.g. 993 for SSL, 143 for unencrypted |
| password | string | yes | The IMAP password or app-specific password |
| username | string | yes | The IMAP username for authentication |
No output schema declared.
No examples provided.
imap_finder IMAP Finder ~91
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.
| Name | Type | Req | Description |
|---|---|---|---|
| imap_provider_name | string | yes | The email provider name to look up, e.g. gmail, outlook, yahoo |
No output schema declared.
No examples provided.
mx_lookup MX Lookup ~58
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to look up MX records for, e.g. example.com |
No output schema declared.
No examples provided.
ptr_lookup PTR Lookup ~79
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.
| Name | Type | Req | Description |
|---|---|---|---|
| ip_address | string | yes | The IP address to look up, e.g. 8.8.8.8 or 142.250.80.46 |
No output schema declared.
No examples provided.
smtp_check SMTP Check ~195
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.
| Name | Type | Req | Description |
|---|---|---|---|
| encryption | string | yes | The encryption protocol: ssl, tls, or none |
| from_email | string | – | Optional sender email address for sending a test email |
| host | string | yes | The SMTP server hostname, e.g. smtp.gmail.com |
| password | string | yes | The SMTP password or app-specific password |
| port | integer | yes | The SMTP port number, e.g. 587 for TLS, 465 for SSL, 25 for unencrypted |
| to_email | string | – | Optional recipient email address for sending a test email |
| username | string | yes | The SMTP username for authentication |
No output schema declared.
No examples provided.
smtp_finder SMTP Finder ~107
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.
| Name | Type | Req | Description |
|---|---|---|---|
| provider_name | string | yes | The email provider name to look up, e.g. gmail, sendgrid, mailgun, outlook |
No output schema declared.
No examples provided.
spf_check SPF Check ~75
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to check SPF records for, e.g. example.com |
No output schema declared.
No examples provided.
spf_generate SPF Generator ~156
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to generate an SPF record for, e.g. example.com |
| hard_fail_boolean | boolean | yes | If true, uses strict -all policy (reject unauthorized senders). If false, uses soft ~all (mark but deliver). |
| provider | string | yes | 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. |
No output schema declared.
No examples provided.
txt_lookup TXT Lookup ~66
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.
| Name | Type | Req | Description |
|---|---|---|---|
| domain_name | string | yes | The domain to look up TXT records for, e.g. example.com |
No output schema declared.
No examples provided.
How do I install the MailX Email Deliverability MCP server?
MailX Email Deliverability is a hosted endpoint at https://themailx.com/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · themailx.com
claude mcp add --transport http com-themailx-email-deliverability 'https://themailx.com/mcp'
What is the MailX Email Deliverability MCP server?
MailX Email Deliverability is an MCP server listed in the public MCP registry as com.themailx/email-deliverability. Check SPF/DKIM/DMARC/BIMI, blacklists, SMTP/IMAP; DNS lookups; generate email DNS records. This page covers its hosted endpoint (https://themailx.com/mcp).
Is the MailX Email Deliverability MCP server safe to use?
MailX Email Deliverability scores 88 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the MailX Email Deliverability MCP server expose?
MailX Email Deliverability exposes 17 tools: audit_domain, spf_check, dkim_check, dmarc_check, bimi_check, and 12 more. Their descriptions and schemas cost roughly 1,756 tokens of context every time the server is loaded.
Does the MailX Email Deliverability MCP server require authentication?
No. We connected to MailX Email Deliverability without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the MailX Email Deliverability MCP server still maintained?
MailX Email Deliverability is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.