The Postbox Tools MCP server,
connected in one click.
Free email checks: 24 blacklists, spoofing/BEC grade, redirect tracing, email spam test, WHOIS. Connect the official Postbox Tools MCP server to Claude, ChatGPT, or Cursor through gate — one gateway URL, no config files, security-checked.
Free to start · No credit card · No hosting needed
Add Postbox Tools to your AI in one minute
Pick your client. Copy, paste, done — or let gate handle sign-ins and policies for you.
claude mcp add --transport http postbox-tools https://mcp.postboxservices.com/mcpRun in your terminal, then restart Claude Code.
Postbox Tools · https://mcp.postboxservices.com/mcp
What your AI can do with Postbox Tools
Real prompts you can type the moment it's connected — no setup, no docs to read.
“Use “check_blacklist”: Check a domain against domain blacklists (Spamhaus DBL, SURBL, URIBL and others), or an IP address against 24 IP blacklists including Spamha.”
“Use “check_spoofability”: Grade how exposed a domain is to email spoofing and business email compromise, from its public DNS (SPF, DMARC policy strength, alignment, l.”
“Use “trace_redirect”: Follow a URL server-side through every HTTP redirect hop to its real final destination - per-hop status, IP, TLS and timing, plus phishing/d.”
“Use “create_mailtest”: Create a disposable test address for a full email deliverability audit (score /10: SPF, DKIM, DMARC + alignment, blacklists, reverse DNS, Sp.”
How secure is the Postbox Tools MCP server?
Every server in the gate directory has to pass the same four checks before your AI can touch it. Here's how Postbox Tools holds up.
Official endpoint
Operated by Postbox Tools (postboxservices.com) at its documented MCP endpoint — not a third-party mirror or community re-host.
No sign-in needed
This server only exposes public data — no account and no credentials are involved when you connect.
Scanned before it goes live
gate checks every tool for prompt injection, hidden instructions, data-exfiltration hints, and over-broad permissions before the server is available through your gateway.
Watched for drift
If Postbox Tools adds or changes tools later, gate re-scans and alerts you — before your AI acts on the change.
Connected in three steps
Connect your gate
Add one gateway URL to Claude, ChatGPT, or any MCP client. One-time setup, about two minutes.
Pick Postbox Tools
Choose Postbox Tools in the gate directory. No sign-in needed.
Use it anywhere
Postbox Tools's tools are live in every AI client you've connected — with rules and logging built in.
Free to start · No credit card · No hosting needed
The actual tools Postbox Tools exposes
Fetched live from the official endpoint and re-checked daily by gate — not marketing copy.
check_blacklist — Check a domain against domain blacklists (Spamhaus DBL, SURBL, URIBL and others), or an IP address against 24 IP blacklists including Spamha
check_spoofability — Grade how exposed a domain is to email spoofing and business email compromise, from its public DNS (SPF, DMARC policy strength, alignment, l
trace_redirect — Follow a URL server-side through every HTTP redirect hop to its real final destination - per-hop status, IP, TLS and timing, plus phishing/d
create_mailtest — Create a disposable test address for a full email deliverability audit (score /10: SPF, DKIM, DMARC + alignment, blacklists, reverse DNS, Sp
get_mailtest_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.
analyze_eml — Run a deliverability/content analysis on a raw RFC 822 email (.eml source: full headers + body). IMPORTANT LIMITS: with no live SMTP session
get_domain_age — Get a domain's registration date and age (young domains have weak sending reputation).
whois_lookup — WHOIS summary for a domain: registrar, created/updated/expires dates, nameservers, DNSSEC, status flags.
Who runs the Postbox Tools MCP server?
The Postbox Tools MCP server at a glance
https://mcp.postboxservices.com/mcpQuestions, answered
Is there an official Postbox Tools MCP server?
Yes — Postbox Tools operates its own remote MCP server at mcp.postboxservices.com. gate connects you to that official endpoint and adds security scanning, per-tool access rules, and an activity log on top.
How do I connect Postbox Tools to Claude or ChatGPT?
Add gate's gateway URL to your AI client once, then pick Postbox Tools in the directory. No account or sign-in is needed. From then on, Postbox Tools's tools are available in every client you've connected to gate.
Do I need to host anything?
No. Postbox Tools runs the server, and gate is fully managed. You just connect one URL — there's nothing to install, deploy, or maintain.
Is the Postbox Tools MCP server safe to connect?
It's the vendor's official endpoint, and gate scans its tools for prompt injection and hidden instructions before it goes live, re-checks it whenever it changes, and lets you allow, block, or require approval for every single tool.
Is it free?
Yes — you can get started with gate for free and connect Postbox Tools in minutes. No credit card required.
Connect more than just Postbox Tools
Every server below works through the same gateway URL — connect once, add tools anytime.
Squarespace DomainsDesignView →Set up Postbox Tools in: Claude · Claude Code · ChatGPT · Cursor · VS Code