Why it matters
These settings protect a domain's email from spoofing and improve inbox delivery. When a domain changes hands, the new owner should set them up before sending mail. A domain with no records may land in spam. They are stored as DNS records, usually TXT. A common mistake is keeping the old owner's records after a sale, which can send mail to the wrong place or fail checks. Review them as part of the transfer.
Source: cloudflare.com