Address records, mail and text records, plus the SPF and DMARC policy that decide whether the domain can send mail. Looked up by our resolver when you press the button — nothing is stored.
A, AAAA, CNAME, MX,
NS, TXT and CAA records.SPF and DMARC as a policy line, because those two
decide whether your mail lands or is thrown away.PTR) instead of a zone.The game behind this: Decode the Hostname — read a router's reverse DNS name
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