Which protocol is commonly used for securing email?

The choice of SSL/TLS as the protocol commonly used for securing email is based on its role in providing cryptographic security for data transmissions over a network, including email communication. SSL (Secure Sockets Layer) and its successor, TLS (Transport Layer Security), establish an encrypted link between the email client and server. This encryption ensures that sensitive email data, such as account credentials and message content, is protected from eavesdropping and tampering while traversing the internet.

In practice, while SMTP (Simple Mail Transfer Protocol) is primarily responsible for sending emails, it does not inherently provide security features. However, SMTP can be secured using SSL/TLS, often referred to as SMTPS (Secure SMTP). This highlights how SSL/TLS is essential for not just any specific component but as a foundational layer for securing email communication effectively.

Other protocols mentioned, such as HTTP (Hypertext Transfer Protocol) and FTP (File Transfer Protocol), serve different purposes. HTTP is used for web traffic and does not provide email security, while FTP is designed for transferring files, lacking the necessary security measures for email transmission as well. Therefore, SSL/TLS is the correct choice for securing email communications through encryption.