Audits and protects sender reputation and inbox placement for permissioned marketing and lifecycle email - SPF, DKIM, and DMARC authentication, domain warmup, bounce and complaint thresholds, and engagement sunsetting - and delivers a scored deliverability audit checklist with a remediation order. Use when someone asks "why are my newsletters going to spam", "how do I set up SPF, DKIM, and DMARC", "is my bounce rate too high", "should I send marketing from a subdomain", or is launching a new sending domain or auditing an existing opted-in email program. Do NOT use for cold outbound infrastructure - lookalike sending domains, mailbox pools, per-mailbox volume caps - use cold-email-deliverability instead; do NOT use to write the emails themselves - use email-drip-builder or email-newsletter-pro instead.
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name: Email Deliverability
description: Audits and protects sender reputation and inbox placement for permissioned marketing and lifecycle email - SPF, DKIM, and DMARC authentication, domain warmup, bounce and complaint thresholds, and engagement sunsetting - and delivers a scored deliverability audit checklist with a remediation order. Use when someone asks "why are my newsletters going to spam", "how do I set up SPF, DKIM, and DMARC", "is my bounce rate too high", "should I send marketing from a subdomain", or is launching a new sending domain or auditing an existing opted-in email program. Do NOT use for cold outbound infrastructure - lookalike sending domains, mailbox pools, per-mailbox volume caps - use cold-email-deliverability instead; do NOT use to write the emails themselves - use email-drip-builder or email-newsletter-pro instead.
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# Email Deliverability
Sender reputation takes months to build and days to destroy, and most teams discover a deliverability problem only after open rates have already cratered. This skill audits and protects inbox placement for permissioned marketing and lifecycle email - authentication, warmup, list hygiene, and engagement - and returns a scored audit with fixes in dependency order. It exists to catch the silent killers (an unenforced DMARC policy, a stale segment, a skipped warmup) before an inbox provider does.
## Operating procedure
Work the steps in order: authentication failures poison every downstream metric, so fix identity before hygiene, and hygiene before engagement.
### Step 1: Gather inputs
Collect these before auditing anything. If a number is estimated, label it a guess and verify against the ESP dashboard before the audit ships.
- Sending domain(s), and whether marketing and transactional mail share one identity.
- ESP(s) in use; shared or dedicated sending IP.
- List size, acquisition sources (signup form, import, purchase - a purchased source is an automatic red flag), and list age.
- Last 30 days of: delivered volume, hard and soft bounce rates, spam complaint rate, open and click rates by segment.
- Google Postmaster Tools access. If the domain is not enrolled, enrolling is the first remediation item - it is the only direct view of how Gmail scores the domain.
- DMARC report destination, if one exists.
### Step 2: Verify authentication by DNS lookup, not by the ESP settings screen