Câu 157: N10-009: CompTIA Network+

A network engineer performed a migration to a new mail server. The engineer changed the MX record, verified the change was accurate, and confirmed the new mail server was reachable via the IP address in the A record. However, users are not receiving email. Which of the following should the engineer have done to prevent the issue from occurring?

1. A. Change the email client configuration to match the MX record.
2. B. Reduce the TTL record prior to the MX record change. — đáp án hiện tại
3. C. Perform a DNS zone transfer prior to the MX record change.
4. D. Update the NS record to reflect the IP address change.