email-deliverability

Make sure email actually reaches inboxes. Use this skill when setting up email authentication (SPF, DKIM, DMARC), diagnosing emails landing in spam, planning a domain reputation strategy, monitoring sender reputation, or hardening against email spoofing. Triggers on email deliverability, SPF, DKIM, DMARC, spam folder, sender reputation, mailbox provider, soft bounces, bounce rate, BIMI, MTA-STS, deliverability audit. Also triggers when a marketing or transactional email isn't reaching users.

Quality

—

Does it follow best practices?

Impact

—

No eval scenarios have been run

Securityby

Passed

No known issues

Quality

Content

92%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, highly actionable skill body with concrete commands, record examples, and a clearly sequenced workflow with validation checkpoints. Its only weakness is progressive disclosure: most detail is inline rather than split across the single reference file.

Suggestions

Split the BIMI setup and content/pattern audit sections into separate referenced files (e.g. references/bimi-setup.md), keeping the SKILL.md as a tighter overview that links out.

Add a second reference for the SPF lookup-limit flattening procedure and reputation-monitoring tool details to reduce inline body length.

Ensure each major pillar (authentication, reputation, list quality) points to a one-level-deep reference for the deeper material rather than carrying it inline.

Dimension	Reasoning	Score
Conciseness	Lean and efficient with no padding about what email or DNS is; assumes Claude's competence and every section earns its place, e.g. direct SPF/DKIM/DMARC record snippets and targeted thresholds.	3 / 3
Actionability	Provides copy-paste-ready executable commands ('dig +short txt example.com'), real record examples, numeric targets (bounce <2%, complaint <0.1%), and concrete ordered fix lists for each authentication record.	3 / 3
Workflow Clarity	An 8-step sequenced workflow with explicit checkpoints and feedback loops, notably the staged DMARC progression (p=none -> pct=10 -> p=reject) with 'watch reports 2-4 weeks' and 'verify with a test send (check headers for dkim=pass)'.	3 / 3
Progressive Disclosure	Has one clearly signaled, one-level-deep reference (references/dmarc-rollout-playbook.md, a real file), but the body is a fairly long monolithic ~270 lines where some sections (BIMI, content/pattern audit) could be split into referenced files for better separation.	2 / 3
	Total	11 / 12 Passed

Description

100%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A high-quality description: concise, third-person, with explicit 'Use when' guidance and a rich set of natural trigger terms. It clearly conveys both capability and trigger conditions with no vague fluff.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete actions ('setting up email authentication (SPF, DKIM, DMARC)', 'diagnosing emails landing in spam', 'planning a domain reputation strategy', 'monitoring sender reputation', 'hardening against email spoofing') rather than vague language.	3 / 3
Completeness	Explicitly answers both what it does and when to use it via an explicit 'Use this skill when...' clause and a dedicated 'Triggers on...' sentence, matching the top anchor.	3 / 3
Trigger Term Quality	Strong coverage of natural user terms ('email deliverability', 'SPF', 'DKIM', 'DMARC', 'spam folder', 'sender reputation', 'soft bounces', 'bounce rate') plus the plain-language trigger 'marketing or transactional email isn't reaching users'.	3 / 3
Distinctiveness Conflict Risk	Occupies a clear niche (email deliverability) with distinct, specific triggers unlikely to fire for unrelated skills.	3 / 3
	Total	12 / 12 Passed

Validation

93%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	15 / 16 Passed

Repository: rampstackco/claude-skills
Commit: f1bc195

Reviewed: 9 days ago

Table of Contents

Discovery Implementation Validation

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