CREST Practitioner Security Analyst (CPSA) Practice

Which protocol primarily handles email delivery?

1. TACACS

2. SMTP

3. SSH

4. Telnet

The correct answer is: SMTP

The protocol that primarily handles email delivery is Simple Mail Transfer Protocol (SMTP). SMTP is specifically designed for sending and relaying email messages between servers. It operates on the application layer of the Internet Protocol Suite and utilizes a straightforward approach to handle the transmission of email from the sender's server to the recipient’s server. SMTP uses a command-response mechanism and is optimized for sending messages efficiently, ensuring that they can traverse various networks and reach their intended destination. Messages sent through SMTP can be delivered to either local mailboxes on the same server or forwarded to other mail servers, making it a foundational component of email communication across the Internet. In contrast, the other protocols mentioned serve different purposes. TACACS (Terminal Access Controller Access-Control System) is primarily used for network access control, SSH (Secure Shell) is designed for secure remote login and command execution, and Telnet is used for remote command-line interface access but does not provide secure communication. These protocols do not facilitate email delivery, which is why SMTP is the correct answer in the context of this question.