To prevent emails from being marked as spam, several DNS records related to email authentication need to be properly configured and updated when there are changes to the email server'scertificates:

A. DMARC (Domain-based Message Authentication, Reporting & Conformance): DMARC records help email servers determine how to handle messages that fail SPF or DKIM checks, improving email deliverability and reducing the likelihood of emails being marked as spam.

B. SPF (Sender Policy Framework): SPF records specify which mail servers are authorized to send email on behalf of your domain. Updating the SPF record ensures that the new email server is recognized as an authorized sender.

C. DKIM (DomainKeys Identified Mail): DKIM adds a digital signature to email headers, allowing the receiving server to verify that the email has not been tampered with and is from an authorized sender. Updating DKIM records ensures that emails are properly signed and authenticated.

D. DNSSEC (Domain Name System Security Extensions): DNSSEC adds security to DNS by enabling DNS responses to be verified. While important for DNS security, it does not directly address the issue of emails being marked as spam.

E. SASC: This is not a relevant standard for this scenario.

F. SAN (Subject Alternative Name): SAN is used in SSL/TLS certificates for securing multiple domain names, not for email delivery issues.

G. SOA (Start of Authority): SOA records are used for DNS zone administration and do not directly impact email deliverability.

H. MX (Mail Exchange): MX records specify the mail servers responsible for receiving email on behalf of a domain. While important, the primary issue here is the authentication of outgoing emails, which is handled by SPF, DKIM, and DMARC.