The security engineer should modify the following to fix the email migration issues:
Email CNAME Record: The email CNAME record must be changed to a type A record pointing to
192.168.1.10. This is because CNAME records should not be used where an IP address (A record) is required.
Changing it to an A record ensures direct pointing to the correct IP.
TXT Record for DMARC: The TXT record must be changed to "v=dmarc ip4:192.168.1.10 include com -all". This ensures proper configuration of DMARC (Domain-based Message Authentication, Reporting
& Conformance) to include the correct IP address and the email service provider domain.
DMARC: Ensuring the DMARC record is correctly set up helps in preventing email spoofing and phishing, aligning with email security best practices.
References:
CompTIA Security+ SY0-601 Study Guide by Mike Chapple and David Seidl
RFC 7489: Domain-based Message Authentication, Reporting & Conformance (DMARC) NIST Special Publication 800-45: Guidelines on Electronic Mail Security