cold-email-deliverability

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---
name: cold-email-deliverability
description: Reviews a cold email draft and its sending setup for deliverability - SPF/DKIM/DMARC alignment, sender reputation and complaint risk, body mechanics (length, links, images, tracking pixels, HTML vs plain text, opt-out), and legal compliance by region. Covers B2B cold outbound and B2C bulk/lifecycle mail. Use whenever the user mentions the spam folder, blacklisting, domain warmup, inbox placement, bounce rates, DMARC, or "why are my emails not landing", even without the word deliverability. Do NOT use for subject lines (mbfinotti/sales-skills@cold-email-subject-line-tester) or cadence (mbfinotti/sales-skills@sales-outbound-sequence). Hygiene and compliance only, never spam-filter evasion.
license: MIT
metadata:
  author: Maya-Beth Finotti
  version: "1.3.2"
---

# Email Deliverability Review

Review a cold email draft and the setup that sends it - authentication, domain architecture, reputation signals, body structure, legal compliance; return a placement-risk report ordered by what actually decides inbox placement.

Label every claim's provenance:

- **provider-verified** - mailbox-provider or standards-body documentation.
- **vendor** - tool-vendor marketing, no independent methodology.
- **contested** - credible sources disagree.
- **practitioner** - expert consensus, uncontrolled.

Never present a vendor number as a law. Where evidence does not exist, say so.

## The placement hierarchy

Encode this order in every review. It is what most advice in this space gets backwards. Effort below is setup and monitoring time and reversibility, never a price.

- value (placement bought): authentication > reputation and complaint control > content structure > word choice
- effort (setup, monitoring, reversibility): reputation and complaint control > authentication == content structure > word choice
- efficiency (do first): authentication > content structure > reputation and complaint control > word choice

Authentication and content structure tie on effort because each is a single one-time hour and each is fully reversible. They differ only in who executes them - DNS access versus the draft's author; this is a re-ranking condition, not an effort difference.

1. **Authentication is a hard gate.** An hour of DNS work, and nothing downstream works without it. SPF/DKIM/DMARC alignment, valid PTR, TLS. Provider-verified: failures now mean rejection (Microsoft `550 5.7.515` since May 5, 2025) or Gmail 4.7.x/5.7.x codes. No copy edit compensates.
2. **Sender reputation and recipient engagement/complaint signals dominate placement.** The largest lever over placement once mail is accepted at all, and the only one of the four that is a standing job rather than a fix. Gmail filters at the mailstream level, not the message level; spam-button complaints are the single largest negative signal (provider-verified mechanics, practitioner-documented).
3. **Content structure is a distant tiebreaker**, cheap enough to stay ahead of reputation work on ratio alone: image-only mail, low text-to-image ratio, HTML with no plain-text part, link-domain reputation - not vocabulary.
4. **"Spam trigger word" lists are largely folklore.** The weakest lever, and last for that reason. No independent controlled study ties word choice, word count, or link count to spam placement (as opposed to reply rate). A clean-reputation domain inboxes "FREE!!! Act now"; a burned domain does not inbox a haiku. Check content anyway - but tell the user plainly, and never hand back a banned-word list as the primary fix.

What this order starves: reputation and complaint control, which ranks second on value yet loses to a cheap tiebreaker on every efficiency round, because it is a standing job with no finish line. Promote it to first whenever the sender intends to keep sending past this campaign, or whenever the Gmail spam rate is already above 0.10% - past that point no authentication or content fix reaches a stream already flagged.

A r