skills.rest
ever-just
ever-justCOMMUNITY
Explore all skills by this author →
WebsiteGitHub

custom-domain-email-dns-diagnosis

Diagnose registrar-versus-DNS-host splits and configure MX, SPF, DKIM, and DMARC records for custom domains.

3|1|Updated Apr 8, 2026
Search Tags:#email#dns#spf#dkim#dmarc#nameservers#mx records
One-click install
npx skills add https://github.com/ever-just/agentskills --skill custom-domain-email-dns-diagnosis-ever-just
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: custom-domain-email-dns-diagnosis
Source: https://github.com/ever-just/agentskills/tree/main/skills/custom-domain-email-dns-diagnosis
Command: npx skills add https://github.com/ever-just/agentskills --skill custom-domain-email-dns-diagnosis-ever-just

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Custom-domain email setup often fails because a domain is registered at one provider (e.g., GoDaddy) while its nameservers are delegated elsewhere (e.g., Vercel, Cloudflare), causing registrar DNS APIs to return 'no zone' errors and leaving users with broken half-configured email. ## Core Features & Use Cases - Registrar vs DNS Host Diagnosis: Uses dig NS and whois to determine who is actually authoritative for a domain's DNS before attempting record writes. - Email Record Architecture: Guides safe addition of MX, SPF, DKIM, and DMARC records, which live in a separate namespace from A/CNAME records and cannot break a live website. - Architecture Matching: Helps choose between native platform mailboxes, forwarding to Gmail, or full Google Workspace based on available infrastructure, and states honest limitations when a setup is impossible. - Use Case: A user's GoDaddy API returns 'no zone' when adding MX records; this Skill identifies that nameservers point to Vercel, writes the records at Vercel instead, and verifies propagation with dig. ## Quick Start Diagnose why email records won't save on my custom domain and tell me where to configure MX, SPF, DKIM, and DMARC.

Frequently Asked Questions about custom-domain-email-dns-diagnosis

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
Why does my registrar DNS API return 'no zone' for my domain?▼

A 'no zone' error means the registrar is not authoritative for the domain because its nameservers are delegated elsewhere, such as Vercel or Cloudflare. Run dig +short NS on the domain to find the real DNS host and write records there instead.

How do I find out who controls DNS for a custom domain?▼

Run dig +short NS on the domain to see which nameservers are authoritative, and use whois to identify the registrar. If they differ, DNS records must be managed at the nameserver host, not the registrar.

Will adding MX or SPF records break my live website?▼

No. MX and TXT records for SPF, DKIM, and DMARC live in a different namespace than the A/CNAME records serving your site, so adding them cannot take the site down. Just add records rather than replacing the entire zone.

What DNS records are needed to send email from a custom domain?▼

Sending as a domain requires an SPF TXT record authorizing senders, a DKIM TXT record with the provider's signing key, and a DMARC policy record. MX alone only handles receiving; deliverability needs all three aligned.

Can a domain have multiple SPF records?▼

No, a domain may have only one v=spf1 TXT record. If you need multiple sending services, merge their include mechanisms into a single SPF record rather than adding a second one.

When should I not use this DNS diagnosis approach?▼

Do not use it for OSINT fingerprinting of an existing email provider, for GoDaddy-specific record-write syntax once GoDaddy is confirmed authoritative, or for writing email copy. Those belong to separate dedicated skills.

Related Skills

Explore More Software Engineering Skills→
yv1ingyv1ing
701

dns-whois

Query DNS records and WHOIS registration data using dig, nslookup, and whois CLIs.

Community
Basic
theslashdojotheslashdojo

domains

Manage and verify Resend sending domains and their DNS records.

Official
Intermediate
ndestatesndestates

amazon-ses-email

Configures Amazon SES sending and receiving for a domain with Laravel integration.

Community
Advanced
ndestatesndestates

aws-route53-dns

Automates AWS Route 53 DNS record management for SES email verification and domain delegation.

Community
Advanced