Where to get the zone file
- Cloudflare: DNS → Records → Import and Export → Export.
- BIND: the file in /etc/bind or /var/named; from a server, dig AXFR example.com @ns1 if zone transfer is allowed.
- Route 53: aws route53 list-resource-record-sets or cli53 export. Many registrars offer a zone export in their panel.
The most common mistakes
The forgotten trailing dot is the classic: “mail.example.com” in the example.com zone becomes mail.example.com.example.com and mail stops arriving. Second is a CNAME next to other records, such as a CNAME and an MX on one name. Third is two SPF records after adding a new email service.
Check what the live zone actually serves: DNS lookup, DNS propagation, domain check. A correct SPF: SPF & DMARC generator.