4 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
A record of mx1.<domain>: looks up the mx1 host under the domain you give (A via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like mx1 without enumerating sub...
AAAA record of mx1.<domain>: looks up the mx1 host under the domain you give (AAAA via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like mx1 without enumerati...
CNAME record of mx1.<domain>: looks up the mx1 host under the domain you give (CNAME via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like mx1 without enumera...
TXT record of mx1.<domain>: looks up the mx1 host under the domain you give (TXT via Cloudflare DoH) and reports whether it exists, its records and TTL. Quick existence check for common hosts like mx1 without enumerating...