io.github.kryptoscan由 GitHub 账号 kryptoscan 发布v0.1.0更新于 Oct 29, 2026
Check SPF, DKIM, DMARC, blocklists, reverse DNS and email headers against Gmail/Yahoo sender rules.
只读的 MCP 服务器，用于诊断邮件送达率：SPF、DKIM、DMARC、黑名单、反向 DNS 与收到的邮件头。
Web executable，通过 Streamable HTTP。 远程服务在工作区中配置后即可从网页运行时运行。
把这段提示词粘贴到 Claude Code、Codex、Cursor 等智能体，或 SourceWeft 对话中。智能体会读取该服务器的安装指南，先向你展示发布者、端点和登录方式，经你同意后再把它添加到你的客户端。密钥不会写进任何命令。
阅读 https://sourceweft.com/mcp/io.github.kryptoscan%2Femail-deliverability-mcp/install.md，并按其中说明把这个 MCP 服务器接入我的客户端。修改任何配置之前，先告诉我它的发布者、端点和登录方式，等我确认。不要把 API 密钥写进命令或我会提交的文件；问我密钥应从哪里获取。把它添加到你客户端的 mcpServers 配置中。
{
"mcpServers": {
"email-deliverability-checker": {
"type": "http",
"url": "https://api.ownmailserver.com/tools/mcp"
}
}
}An MCP server that lets Claude (or any MCP client) diagnose email deliverability:
check_domain: SPF (including the 10-DNS-lookup limit), DMARC policy and reporting, DKIM keys on common selectors, and MX records, with a ranked list of problems and the fix for each. It also names the email services a domain uses (Google Workspace, SendGrid, Amazon SES and others).check_sending_ip: reverse DNS (PTR) and whether it resolves back to the IP, plus listings on Spamhaus ZEN, Barracuda, SpamCop, PSBL, Mailspike and UCEPROTECT level 1.check_email_headers: paste a received message's headers and check them against Gmail's and Yahoo's sender requirements: SPF, DKIM, DMARC, From alignment, one-click unsubscribe (and whether DKIM covers it), TLS, reverse DNS and Message-ID.Every tool is read-only: it reads public DNS or the text you give it. Nothing is sent anywhere else, and no account or API key is needed.
A hosted copy runs at:
Add it to Claude as a custom connector (Settings → Connectors → Add custom connector), or in Claude Code:
It's free and needs no account. It's rate-limited per IP, uses public DNS resolvers (so Spamhaus results show as "refused"; see below), and stores nothing. For heavy use or a real Spamhaus answer, run your own copy.
Requires Node.js 20 or later.
Claude Code
Claude Desktop (claude_desktop_config.json)
Docker
BLOCKLIST_DNS mattersSpamhaus refuses queries that arrive through big public resolvers (8.8.8.8, 1.1.1.1 and the like) and answers 127.255.255.x instead. Many blocklist checkers misread that as "listed". This server reports it as refused, meaning unknown, and says so. To get a real Spamhaus answer, point BLOCKLIST_DNS at a recursive resolver of your own, such as unbound on 127.0.0.1.
include: and redirect= recursively and count every include, a, mx, ptr, exists and redirect term, as RFC 7208 does. More than 10 is a permanent error at most receivers.dkim_selectors (find it in the s= value of a message's DKIM-Signature header). Domains that answer every name (wildcard DNS) are detected and not reported as having keys.Authentication-Results header, which is what the recipient's mailbox provider concluded, and the newest Received hop that names the sending server.example.co.uk). It's not a full Public Suffix List lookup, so unusual suffixes may be misjudged.Built by OwnMailServer, which runs dedicated email sending for businesses that send 250,000 to 1,000,000 emails a month: your own server and IP, a Resend-style API and SMTP, managed warm-up and daily monitoring. OwnMailServer accounts also get a Claude connector for their own sending data: delivery stats, bounces, complaints and message history.
The same checks are available as free web tools: the email health checker and the bulk sender checker.
MIT
来源：README.md，提交 5981484
Check a domain's email DNS
Check a domain's SPF (including the 10-DNS-lookup limit), DMARC policy and reporting, DKIM keys on common selectors, and MX records. Returns problems ranked by severity with the fix for each, plus the email services the domain uses.
domain必填dkim_selectorsCheck a sending IP
Check a mail server's IP: reverse DNS (PTR) and whether it resolves back to the IP, and listings on Spamhaus ZEN, Barracuda, SpamCop, PSBL, Mailspike and UCEPROTECT level 1. A refused Spamhaus query is reported as unknown, never as a listing.
ip必填Check email headers
Check a received email's headers against Gmail's and Yahoo's bulk sender requirements: SPF, DKIM and DMARC results, From domain alignment, one-click unsubscribe (and whether DKIM covers it), TLS, reverse DNS and Message-ID. Use the full headers as the recipient got them (Gmail: Show original).
headers必填已满足适用检查项的 100%
该评分衡量此收录条目的完整程度，依据注册中心条目、端点与公开来源计算得出。它不是对服务器本身的评价，也不表示服务器安全或当前可用：可连通性是带日期的检查结果，评分也不包含安装量或用户评价。
https://api.ownmailserver.com/tools/mcpclaude mcp add --transport http email-deliverability https://api.ownmailserver.com/tools/mcpclaude mcp add email-deliverability -- npx -y email-deliverability-mcp{ "mcpServers": { "email-deliverability": { "command": "npx", "args": ["-y", "email-deliverability-mcp"] } }}docker build -t email-deliverability-mcp .docker run -i --rm email-deliverability-mcpnpm installnpm test # unit tests with a fake DNS resolvernpm run build # compiles to dist/npm run start:http # the HTTP version (PORT, MCP_PATH, TRUST_PROXY, RATE_LIMIT, GLOBAL_LIMIT)