Michael wants to secure mail being retrieved via the Post Office Protocol Version 3 (POP3) because he knows that it is unencrypted by default. What is his BEST option to do this while leaving POP3 running on its default port?

Michael knows that POP3 runs on port 110 by default and that TLS (via STARTTLS as an extension) allows POP3 clients to request a secure connection without needing to use the alternate port 995 used in some configurations. Port 25 is the default port for Simple Mail Transfer Protocol (SMTP), and IKE is used for IPSec.