Which FortiMail antispam technique can the administrator use to prevent this scenario?

A FortiMail administrator is investigating a sudden increase in DSNs being delivered to the protected domain for undeliverable email messages. After searching the logs, the administrator identifies that the DSNs were not generated as a result of any outbound email sent from the protected domain.

Which FortiMail antispam technique can the administrator use to prevent this scenario?
A . Spam outbreak protection
B. Bounce address tag validation
C. Spoofed header detection
D. FortiGuard IP Reputation

Answer: A

Explanation:

Reference: https://docs.fortinet.com/document/fortimail/6.2.0/administration-guide/769204/managing-the-mail-queue