Use when pointing a domain at a host or fixing broken HTTPS — delegating nameservers, writing A/AAAA/CNAME/ALIAS/MX/TXT/CAA rows, apex vs www, standing up auto-renewing TLS, and cutting nameservers over without downtime. NOT inbox placement or warmup (that is `email-deliverability`), NOT what runs behind the name (that is `deployment`).
