POP3S stands for which expansion?

• A. Post Office Protocol Secure 3
• B. Post Office Protocol 3 Security
• C. Post Office Protocol 3 Securely
• D. Post Office Protocol 3 Secure

Answer: (A)

POP3S is the secure version of the POP3 protocol, meaning the session is encrypted with TLS/SSL. The S stands for Secure, and the 3 is the version number. So the standard expansion is Post Office Protocol Secure 3. The other word forms don’t match how this acronym is normally written (Security, Securely), and placing the words in a different order doesn’t reflect the established naming. In practice, POP3S is POP3 over TLS/SSL, typically using a port like 995.