CREST Practitioner Security Analyst (CPSA) Practice

In SMTP, which command is utilized to specify the recipient of an email?

1. MAIL

2. DATA

3. RCPT

4. HELO

The correct answer is: RCPT

In the context of the Simple Mail Transfer Protocol (SMTP), the command used to specify the recipient of an email is "RCPT". When a client is sending an email, after initiating the transmission with the "MAIL" command (which indicates the sender's address), the "RCPT" command is then used to list the addresses of the intended recipients. This command is crucial as it informs the SMTP server who should receive the email. Each recipient can be specified in a separate "RCPT" command, allowing for multiple recipients to be addressed within a single email transaction. The use of this command is a fundamental step in the SMTP protocol workflow, ensuring that the email is directed to the correct destination as intended by the sender. Other commands serve different purposes: "MAIL" designates the sender's email address, "DATA" is used to indicate that the following lines will contain the actual message body, and "HELO" is used to initiate the communication between the client and server. Understanding these distinctions is essential for grasping how email delivery works within SMTP.