com.postboxservicesPublished by postboxservices.comOfficial publisherv0.2.0Updated Nov 14, 2026
Free email checks: 24 blacklists, spoofing grade, redirects, spam test, WHOIS, BIMI, AI readiness.
Remote MCP server for email security and deliverability checks: blacklists, spoofing grades, redirect tracing, mail tests, WHOIS and domain age.
Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.
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.postboxservices%2Fpostbox-tools/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.Add this to your client's mcpServers config.
{
"mcpServers": {
"postbox-tools": {
"type": "http",
"url": "https://mcp.postboxservices.com/mcp"
}
}
}Email blacklist check
Check a domain against domain blacklists (Spamhaus DBL, SURBL, URIBL and others), or an IP address against 24 IP blacklists including Spamhaus ZEN, Barracuda and SpamCop. Checks the exact target given: domains are not resolved to IPs. Returns per-list listing status.
targetrequiredSpoofing / BEC exposure check (A-F grade)
Grade how exposed a domain is to email spoofing and business email compromise, from its public DNS (SPF, DMARC policy strength, alignment, live lookalike domains). Returns an A-F grade with findings.
domainrequiredURL redirect chain tracer
Follow a URL server-side through every HTTP redirect hop to its real final destination - per-hop status, IP, TLS and timing, plus phishing/deliverability flags (cross-domain jumps, https downgrades, meta/JS redirects). Fetching is SSRF-hardened (private ranges blocked, HTTPS-only, per-hop validation); how it works: https://redirect.postboxservices.com/
urlrequiredStart an email deliverability test
Create a disposable test address for a full email deliverability audit (score /10: SPF, DKIM, DMARC + alignment, blacklists, reverse DNS, SpamAssassin content, Gmail/Yahoo bulk-sender compliance). The USER must then send an email from the system they want to test to the returned address, after which get_mailtest_result returns the score.
Takes no parameters.
Get an email deliverability test result
Fetch the score and breakdown of a mail test created with create_mailtest, once the user has sent their email to the disposable address.
idrequiredAnalyze a raw email file (.eml)
Run a deliverability/content analysis on a raw RFC 822 email (.eml source: full headers + body). IMPORTANT LIMITS: with no live SMTP session, SPF, blacklist and reverse-DNS cannot be verified from a file - for the authoritative score use create_mailtest instead.
emlrequiredDomain age lookup
Get a domain's registration date and age (young domains have weak sending reputation).
domainrequiredWHOIS lookup
WHOIS summary for a domain: registrar, created/updated/expires dates, nameservers, DNSSEC, status flags.
domainrequired44% 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.
Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.
A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.
