email-deliverability-audit 邮箱可发送性审计
Four sequential DNS gates decide whether an email address can actually receive mail — before your campaign finds out the hard way.
四道顺序 DNS 闸门，在邮件发出之前判定一个地址到底能不能收信。
Why / 为什么
Bounce rates above ~5% push campaigns into spam folders and burn domain reputation. Most list-cleaning tools hand you a score with no evidence behind it. This skill makes the agent run the checks itself — every verdict traces to a DNS query made during that run, and a failed probe is recorded as unverified, never guessed.
退信率超过 ~5%，campaign 就会开始进垃圾箱、烧域名信誉。大多数清洗工具只给一个没有证据的分数。这个 skill 让 agent 自己跑检查——每个判定都能追溯到当次真实 DNS 查询；探测失败就如实记为 unverified，绝不猜。
How it works / 四道闸
Gate 1 Format → Gate 2 Dead domain (A/NS) → Gate 3 MX → Gate 4 Role & placeholder
| Verdict | Meaning |
|---|
sendable | passed all four gates |
risky | passed gates 1–3; role account or placeholder pattern at gate 4 |
dead | failed a gate in 1–3, with the deciding gate recorded |
Batch mode: CSV in, CSV out, output rows match input rows 1:1. Integrity rule: never invent a pass.
批量模式：CSV 进 CSV 出，输出行与输入行 1:1 对应。诚信铁律：绝不编造通过。
Worked example — a 6-sample DNS audit (2026-09)
| Address | Verdict | Deciding gate |
|---|
name@gmail.com | sendable | passed all four |
team@company.com.au | sendable | MX present |
info@shop.com | risky | gate 4: role account |
13800@example.com | risky | gate 4: all-digit local part |
bad@@example.com | dead | gate 1: format |
site@australia.gov.au | dead | gate 3: live website, no MX |
The last row is the gate-3 lesson in one address: a resolving domain with a healthy website can still be unable to receive mail. The site was up; the mail was not.
最后一行就是 Gate 3 的活教材：域名能解析、网站活得好好的，邮件照样收不了——网站在线，收信离线。
Install / 安装
# Claude Code — the clone IS the install
git clone https://github.com/ChenneyZhuang/email-deliverability-audit ~/.claude/skills/email-deliverability-audit
# Hermes
cp -r email-deliverability-audit ~/.hermes/profiles/<profile>/skills/
One SKILL.md, zero dependencies beyond dig or a Python DNS resolver. Runs on Claude Code, DSH, Hermes, and Codex.
单个 SKILL.md，除 dig 或 Python DNS 解析库外零依赖。Claude Code / DSH / Hermes / Codex 通用。
Honest limitations / 如实说明局限
- Gate 4 flags role accounts as
risky, not dead — role-account deliverability varies by receiver.
- A passing audit proves the domain can receive mail; it cannot prove this specific mailbox exists (no SMTP RCPT probing).
- The optional
verified_web column raises confidence; it never upgrades a verdict.
MIT licensed. v0.2.0 — live-tested on real DNS. / MIT 许可，v0.2.0，真 DNS 实测通过。
