Email Service
cohen-liel/hivemind
Email sending patterns for transactional and marketing emails.
Check email deliverability and DNS configuration. An agent skill from guia-matthieu/clawfu-skills.
Install Deliverability Checker
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checker --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/email-tools/deliverability-checker .claude/skills/deliverability-checker && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .claude/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checkerType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checker --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/email-tools/deliverability-checker .agents/skills/deliverability-checker && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .agents/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checker --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/email-tools/deliverability-checker .cursor/skills/deliverability-checker && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .cursor/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/guia-matthieu/clawfu-skills.git --path skills/email-tools/deliverability-checker--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checker --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/email-tools/deliverability-checker .gemini/skills/deliverability-checker && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .gemini/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checkerInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/email-tools/deliverability-checker .github/skills/deliverability-checker && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .github/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install guia-matthieu/clawfu-skills deliverability-checker --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/guia-matthieu/clawfu-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/email-tools/deliverability-checker .opencode/skills/deliverability-checker && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "deliverability-checker" agent skill from https://github.com/guia-matthieu/clawfu-skills/tree/main/skills/email-tools/deliverability-checker into .opencode/skills/deliverability-checker/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "deliverability-checker", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
deliverability-checker- GitHub stars
- 150
- Token cost
- ~1.1k tokens
- SKILL.md length
- 270 words
- Files
- 3 (incl. scripts)
- Skills in repo
- 31
- Repo updated
- First seen
- Licence
- MIT
At a glance
Check email deliverability and DNS configuration. An agent skill from guia-matthieu/clawfu-skills.
- : diagnosing email delivery issues
- SKILL.md covers When to Use This Skill, What Claude Does vs What You…, Dependencies and Commands, plus 8 more sections
- Runs Python scripts from its folder; calls python and pip
- Setting up new email domains
What it does
Deliverability Checker is an agent skill from guia-matthieu/clawfu-skills. Check email deliverability and DNS configuration. Use when: diagnosing email delivery issues; setting up new email domains; auditing email authentication; checking SPF/DKIM/DMARC; troubleshooting spam folder issues
Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 3 other files, including scripts (for example `scripts/main.py`).
It sits in Backend & APIs, covering Transactional email. It works with SendGrid. The repository describes itself as: 172 expert marketing skills for AI agents — ClawFu MCP Server. The licence is MIT.
When your agent uses it
- : diagnosing email delivery issues
- Setting up new email domains
- Auditing email authentication
- Checking SPF/DKIM/DMARC
Example prompts
- “/deliverability-checker”
Requirements
- Python 3
What it can do on your machine
Read from SKILL.md and the folder at commit 4108f5c. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 2 files in scripts/ (Python), which the agent can run.
Shell commands in SKILL.md call:
pythonpip
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use pip, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Deliverability Checker loads about 1.1k tokens when it runs. Until then it costs about 59 tokens; SKILL.md has 270 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
SKILL.md
The full file from guia-matthieu/clawfu-skills at commit 4108f5c, republished under its MIT licence (© guia-matthieu). 270 words, ~1,123 tokens.
Download SKILL.mdSave it as
.claude/skills/deliverability-checker/SKILL.md (or your agent's skills folder). This skill also uses 2 other files; get the full folder from GitHub.- name
- deliverability-checker
- description
- Check email deliverability and DNS configuration. Use when: diagnosing email delivery issues; setting up new email domains; auditing email authentication; checking SPF/DKIM/DMARC; troubleshooting spam folder issues
- license
- MIT
- metadata.author
- ClawFu
- metadata.version
- 1.0.0
- metadata.mcp-server
- @clawfu/mcp-skills
Email Deliverability Checker
Diagnose email deliverability issues by checking SPF, DKIM, DMARC, and other DNS records - fix why your emails land in spam.
When to Use This Skill
- Delivery troubleshooting - Emails landing in spam
- New domain setup - Configure email authentication
- Migration audit - Verify email config after domain change
- Client onboarding - Check client email health
- Compliance check - Ensure proper authentication
What Claude Does vs What You Decide
| Claude Does | You Decide |
|---|---|
| Structures analysis frameworks | Metric definitions |
| Identifies patterns in data | Business interpretation |
| Creates visualization templates | Dashboard design |
| Suggests optimization areas | Action priorities |
| Calculates statistical measures | Decision thresholds |
Dependencies
pip install dnspython clickCommands
Full Audit
python scripts/main.py audit example.com
python scripts/main.py audit example.com --output report.htmlCheck SPF
python scripts/main.py spf example.comCheck DKIM
python scripts/main.py dkim example.com --selector google
python scripts/main.py dkim example.com --selector defaultCheck DMARC
python scripts/main.py dmarc example.comCheck MX Records
python scripts/main.py mx example.comExamples
Example 1: Full Email Audit
python scripts/main.py audit acme-corp.com
# Output:
# Email Deliverability Audit: acme-corp.com
# ──────────────────────────────────────────
# MX Records: ✓ Found (Google Workspace)
# SPF: ✓ Valid
# DKIM (google): ✓ Valid
# DMARC: ✗ Missing (CRITICAL)
#
# Score: 75/100
#
# Issues Found:
# 1. [CRITICAL] No DMARC record found
# Fix: Add TXT record for _dmarc.acme-corp.com
# Value: v=DMARC1; p=none; rua=mailto:dmarc@acme-corp.comExample 2: Diagnose SPF Issues
python scripts/main.py spf newsletter-sender.com
# Output:
# SPF Analysis: newsletter-sender.com
# ────────────────────────────────────
# Record: v=spf1 include:_spf.google.com include:sendgrid.net ~all
#
# Status: ✓ Valid
#
# Authorized Senders:
# - Google Workspace (include:_spf.google.com)
# - SendGrid (include:sendgrid.net)
#
# Policy: ~all (soft fail)
# Warning: Consider changing to -all (hard fail) for better securityEmail Authentication Records
| Record | Purpose | Location |
|---|---|---|
| SPF | Authorize sending servers | TXT on root domain |
| DKIM | Cryptographic signature | TXT on selector._domainkey |
| DMARC | Policy and reporting | TXT on _dmarc subdomain |
| MX | Mail delivery servers | MX on root domain |
Common SPF Includes
| Provider | SPF Include |
|---|---|
| Google Workspace | include:_spf.google.com |
| Microsoft 365 | include:spf.protection.outlook.com |
| SendGrid | include:sendgrid.net |
| Mailchimp | include:servers.mcsv.net |
| Amazon SES | include:amazonses.com |
DKIM Selectors by Provider
| Provider | Common Selector |
|---|---|
| Google Workspace | google |
| Microsoft 365 | selector1, selector2 |
| SendGrid | s1, s2 |
| Mailchimp | k1 |
Deliverability Score Factors
| Factor | Weight | Impact |
|---|---|---|
| Valid MX | 20% | Can't receive replies |
| Valid SPF | 25% | Server authorization |
| Valid DKIM | 25% | Message integrity |
| Valid DMARC | 30% | Policy enforcement |
Skill Boundaries
What This Skill Does Well
- Structuring data analysis
- Identifying patterns and trends
- Creating visualization frameworks
- Calculating statistical measures
What This Skill Cannot Do
- Access your actual data
- Replace statistical expertise
- Make business decisions
- Guarantee prediction accuracy
Related Skills
- dns-audit - Full DNS health check
Skill Metadata
- Mode: centaur
category: email-tools
subcategory: deliverability
dependencies: [dnspython]
difficulty: beginner
time_saved: 2+ hours/week© guia-matthieu, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 2 other files (scripts) in skills/email-tools/deliverability-checker of guia-matthieu/clawfu-skills.
- SKILL.md
- scripts/main.py
- scripts/requirements.txt
Open the folder on GitHubat commit 4108f5c
Compare with similar skills
Deliverability Checker next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Deliverability Checker this skillguia-matthieu/clawfu-skills | 150 | — | ~1.1k | Automated safety check: Pass | MIT | |
| Email Servicecohen-liel/hivemind | 110 | — | ~1.8k | Automated safety check: Pass | Apache-2.0 | |
| Email Connectorericrisco/rsc-harness | 180 | — | ~3.1k | Automated safety check: Pass | MIT | |
| Emailmagnus919/agent-skills | 115 | — | ~2.4k | Automated safety check: Pass | MIT | |
| Converting Email Templatesaiskillstore/marketplace | 433 | — | ~1.8k | Automated safety check: Pass | None | |
| Lifecycle Messagingavelikiy/great_cto | 102 | — | ~1.3k | Automated safety check: Pass | MIT |
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Related
Works with
Categories
Questions about Deliverability Checker
What does Deliverability Checker do?
Check email deliverability and DNS configuration. An agent skill from guia-matthieu/clawfu-skills. Deliverability Checker is an agent skill from guia-matthieu/clawfu-skills. Check email deliverability and DNS configuration.
When should I use Deliverability Checker?
Deliverability Checker fits situations like: : diagnosing email delivery issues; setting up new email domains; auditing email authentication; checking SPF/DKIM/DMARC.
How do I install Deliverability Checker in Claude Code?
Run `npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a claude-code`. Or copy the skill folder (skills/email-tools/deliverability-checker in guia-matthieu/clawfu-skills) into .claude/skills/deliverability-checker in your project. Claude Code loads it when a task matches its description.
How do I install Deliverability Checker in Codex?
Run `npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a codex`. Or copy the skill folder (skills/email-tools/deliverability-checker in guia-matthieu/clawfu-skills) into .agents/skills/deliverability-checker in your project. Codex loads it when a task matches its description.
Can I use Deliverability Checker in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add guia-matthieu/clawfu-skills --skill deliverability-checker -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/deliverability-checker, .gemini/skills/deliverability-checker, .github/skills/deliverability-checker and .opencode/skills/deliverability-checker in your project.
What does Deliverability Checker need to run?
Going by SKILL.md and its folder, Deliverability Checker needs Python for the scripts in its folder and the command-line tools its instructions call (python and pip). Our summary lists: Python 3.
Does Deliverability Checker access the network?
SKILL.md contains no URLs. Its commands use pip, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Deliverability Checker safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does Deliverability Checker use?
Deliverability Checker is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Deliverability Checker use?
About 1.1k tokens (SKILL.md is roughly 4.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Deliverability Checker?
Skills that share tags, products or a category with Deliverability Checker: Email Service (cohen-liel/hivemind, 110 stars), Email Connector (ericrisco/rsc-harness, 180 stars), Email (magnus919/agent-skills, 115 stars) and Converting Email Templates (aiskillstore/marketplace, 433 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Deliverability Checker?
guia-matthieu (a GitHub user) maintains it in guia-matthieu/clawfu-skills, which has 150 GitHub stars. The repository holds 31 skills in this directory. The repository was last updated on October 1, 2026.
Source: guia-matthieu/clawfu-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.