What does the SMTP command STARTTLS do?

The STARTTLS command plays a crucial role in email communication by enhancing the security of the connection. Specifically, it upgrades an existing standard unsecured SMTP connection to a secure encrypted connection using Transport Layer Security (TLS). This means that when a mail server receives a STARTTLS command, it will respond by initiating the process to establish a secure channel.

This is important because, without encryption, email communications could be intercepted, read, or tampered with during transmission. By using STARTTLS, organizations can protect sensitive information contained in emails from unauthorized access, ensuring confidentiality and data integrity while sending messages over the internet.

Other options do not accurately describe the function of STARTTLS. For instance, it does not create logs of email transactions, request email receipts, or reset connections. Its sole purpose is to facilitate a secure environment for email transmission.