Dns checker

Skill alycd/agent-skills/.claude/skills/dns-checker

Claude Agent Skills

Install

npx -y skills add alycd/agent-skills --skill dns-checker

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

2 things to look at

no licenseNo license file was found in the repository. Code published without one is not open source by default, so using it at work is a question for whoever answers licensing questions where you are.
0 stars0 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

What its author says it does

Copied from the file, not written here

Check DNS records for a sending domain against tinyEmail's required DKIM, SPF, and DMARC configuration. Use when verifying customer email setup, checking DNS propagation, or diagnosing delivery issues. Triggers: "check dns", "verify dns", "dns check", "check dkim", "check spf", "check dmarc", "dns settings", "email dns".

SKILL.md

3.2 KB, 831 tokens by cl100k_base, as published. Nobody here has run it

DNS Checker

Verifies that a customer's sending domain has the correct DKIM, SPF, and DMARC DNS records required by tinyEmail.

Required records

DKIM (2 CNAME records)

Selector	Host	Expected value	Type
tec1	`tec1._domainkey.{domain}`	`tec1.dkim.tinyemail.com`	CNAME
tec2	`tec2._domainkey.{domain}`	`tec2.dkim.tinyemail.com`	CNAME

SPF (1 TXT record)

Host	Must include	Type
`{domain}`	`include:_spf.tinyemail.com`	TXT

Full expected value: v=spf1 include:_spf.tinyemail.com -all

DMARC (1 TXT record)

Host	Must start with	Type
`_dmarc.{domain}`	`v=DMARC1`	TXT

Full expected value: v=DMARC1; p=none; sp=none; rua=mailto:[email protected]; ruf=mailto:[email protected]; fo=1; rf=afrf; pct=100; ri=86400

Instructions

Given a domain (e.g. mail.acme.com), run the following checks in order using dig. Use +short for clean output.

Step 1 — Check DKIM tec1

dig CNAME tec1._domainkey.{domain} +short

Pass: output contains tec1.dkim.tinyemail.com Fail: empty, NXDOMAIN, or wrong value

Step 2 — Check DKIM tec2

dig CNAME tec2._domainkey.{domain} +short

Pass: output contains tec2.dkim.tinyemail.com Fail: empty, NXDOMAIN, or wrong value

Step 3 — Check SPF

dig TXT {domain} +short

Pass: one of the TXT records contains include:_spf.tinyemail.com Fail: no TXT record contains the include, or record is missing entirely

Note: A domain may have multiple TXT records. Scan all of them — pass if any contains the required include.

Step 4 — Check DMARC

dig TXT _dmarc.{domain} +short

Pass: output contains a record starting with v=DMARC1 Fail: no DMARC record found

Step 5 — Report results

Output a clear summary table:

DNS Check Results for: {domain}
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✅ DKIM tec1   tec1._domainkey.{domain} → tec1.dkim.tinyemail.com
✅ DKIM tec2   tec2._domainkey.{domain} → tec2.dkim.tinyemail.com
✅ SPF         {domain} includes include:_spf.tinyemail.com
❌ DMARC       _dmarc.{domain} — no record found
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3/4 checks passed. Action required: DMARC record missing.

For each failure, include:

What was found (the actual DNS value, or "no record")
What was expected
The exact record the customer needs to add

Step 6 — Determine overall result

All 4 pass → DNS is correctly configured. Step is complete — mark done.
Any fail → DNS not ready. Report failures. Do NOT mark the step done (for use in durable-workflow retry scenarios).