Understanding Cisco Cybersecurity Operations Fundamentals (CBROPS) — Question 219

What is email greylisting by the mail transfer agent?

Answer options

• A. denying any email from a sender it does not recognize
• B. returning emails that are potential phishing attempts
• C. allowing emails from unknown senders temporarily
• D. quarantining emails sent from outside of the organization

Correct answer: A

Explanation

The correct answer is A, as greylisting involves temporarily blocking emails from unknown senders until the sender is acknowledged. Options B, C, and D describe different email handling strategies, but they do not accurately define greylisting, which specifically focuses on the initial denial of emails from unfamiliar sources.