Deliverability Triage
When bounces climb, the reflex is to re-verify the list. Nine times out of ten that's the wrong lever. This skill pulls the actual bounce reasons from EmailBison, breaks them down by receiving mail provider and SMTP code, and cross-references verifier verdicts to find the one real cause, whether that's a reputation block, a catch-all dead mailbox, or a policy rejection from a gateway like Mimecast. It ends with the one right action, not a guess paid for with credits.
Pipeline Playbooks · Open Source, MIT Licensed
Diagnoses a bounce spike by ESP and SMTP code before touching anything, because re-verifying the list fixes exactly one of five possible causes.
When to use this
- Bounce rate looks high on any campaign
- Emails aren't landing or replies dried up
- Tempted to re-verify a list
- Senders showing disconnected
- Before any reaction to a bounce alert
What it covers
- Thresholds: sustained >6% bounce across 2+ days, ignore single-day spikes
- Disconnected senders: ignore up to roughly 10 per workspace
- Pulling real bounce reasons from EmailBison's replies feed
- ESP breakdown by MX lookup to catch Mimecast and Barracuda policy rejections
- SMTP code bucketing: 5.1.x dead address vs 5.7.x reputation block
- Cross-referencing bounces against verifier verdicts (valid, valid-risky, invalid)
- The decision tree matching each diagnosis to its lever, and what isn't the lever
- Why EmailBison's 'unverified' lead flag means nothing
Install just this skill
Every skill folder is self-contained. Run this from your project root to pull just this one into .claude/skills/deliverability-triage/:
npx degit joelwylie7/cold-email-playbooks/.claude/skills/deliverability-triage .claude/skills/deliverability-triage
Want the whole system, not just one skill?
Related skills
List Hygiene
The mandatory final pass every lead list gets before it touches a sending tool: dedup, exclusion lists, and an automatic MX check that drops Mimecast and Barracuda domains.
Email Verification
Runs Kitt verification on lists you bring from elsewhere, and draws the hard line on the one mistake that costs money for nothing: re-verifying an already-verified AI Ark export.
Sender Scaling
The volume discipline for cold email senders: 1 a day until engagement proves the campaign, then 3, with further growth always coming from more senders, never higher limits.