Email Deliverability Audit
Diagnostic audit for a running cold email program.
Install
npx skills add growthenginenowoslawski/coldoutboundskills --skill email-deliverability-audit -g -a claude-code -y- Repository
- growthenginenowoslawski/coldoutboundskills797
- Category
- Testing
- Updated
- 1mo ago
- License
- MIT
- Context cost
- Mediumabout 3,000 tokens
- Runs scripts
- Yes, review before use
What it does
Diagnostic audit for a running cold email program. Checks domain authentication (SPF/DKIM/DMARC), inbox health/reputation from Smartlead, bounce rate by inbox type, and optionally runs a spam placement test via Smartlead's Smart Delivery API. Outputs markdown report + CSV with per-domain/per-inbox scores and concrete action items. Use when reply rates drop, when bounces spike, when onboarding someone else's account, or as a weekly/monthly health check.
Email Deliverability Audit
If your positive reply rate is dropping and you don't know why, start here. Most of the time the problem is deliverability, your emails aren't reaching inboxes. This skill tells you what's broken.
What it checks
| Layer | What | How |
|---|---|---|
| DNS auth | SPF, DKIM, DMARC present on each sending domain | dig commands |
| Inbox health | Warmup status, reputation, blocks, connection failures | Smartlead email-accounts API |
| Volume health | Daily sent trending, capacity utilization | Smartlead analytics |
| Send + reply rate per inbox | Sent count, reply count, reply rate % over lookback period | Smartlead campaign analytics |
| Bounce rate | Per-inbox and per-domain bounce rate over last 30 days | Smartlead campaign analytics |
| Spam placement | Real inbox-vs-spam test via Smartlead Smart Delivery | optional |
The 1% rule, and the floors that gate it
A healthy domain replies at 1% or better after 200 emails sent. Below 1% on a fair sample, something is broken, and if it stays broken the domain gets cancelled.
The 1% rule is one number: the same 1% that flags a domain here is the line that retires it in
/inbox-lifecycle-manager. What separates "flag" from "cancel" is not a softer second threshold, it is the floors. Below a floor, the answer is "we don't know yet", which is a legitimate
output rather than a failure.
| Judgment | Floor before it counts |
|---|---|
| Reply rate | 200 sends in the window |
| Bounce rate | 50 sends |
| Bounce composition (which bucket) | 30 classified bounces for that domain |
| Any cancel decision | 30 days of domain age; unknown age counts as young |
| Placement test | 100-300 senders per test |
Reporting 0.00% reply on 14 sends as a failure, or condemning a three-week-old domain that has
not finished ramping, is how healthy domains get killed.
