What is the main difference between whitelisting and blacklisting approaches in email filtering?

The distinction between whitelisting and blacklisting in email filtering is primarily centered around the permissions granted to senders. Whitelisting specifically approves a defined list of trusted senders whose emails are permitted to reach the recipient's inbox. This means that any sender not included in the whitelist is automatically blocked, enhancing security by minimizing the risk of unwanted or potentially harmful emails.

Conversely, blacklisting involves blocking known malicious or unwanted senders while allowing all others. This method focuses on identifying and restricting only those entities that have been flagged as threats, which can sometimes allow harmful emails from unrecognized senders to reach the inbox.

The correct answer highlights how whitelisting functions as a safeguard by permitting only designated senders, while blacklisting actively protects users by identifying and blocking potential threats. This fundamental understanding of the two approaches clarifies their operational differences and helps users choose suitable filtering strategies based on their security needs.