The implementation of anti-malware and anti-phishing controls on centralized email servers is an example of...

 Anti-Malware and Anti-Phishing Controls:

These are technical controls as they involve the use of technology to detect and mitigate malware and phishing threats.

 Application Context:

Centralized email server protections are technical implementations to secure communication channels.

 Supporting Reference:

CCISO materials categorize anti-malware and anti-phishing measures as technical controls essential for defending against cyber threats.