CREST Practitioner Security Analyst (CPSA) Practice 2025 - Free CPSA Practice Questions and Study Guide.

The command used to initiate a mail transaction in the Simple Mail Transfer Protocol (SMTP) is "MAIL." This command is used by the client to specify the sender's email address and to start the process of sending an email message. After issuing the MAIL command, the client typically follows it up with the RCPT command to specify the recipient(s) and then the DATA command to transfer the email content.

Understanding the sequence and purpose of these commands is essential for anyone working with email protocols. The MAIL command is the first step in establishing the context of the email transaction, making it a fundamental aspect of SMTP operations.