What are the different authentication mechanisms supported by SMTP for securing email communication?

What are the different authentication mechanisms supported by SMTP for securing email communication?

SMTP (Simple Mail Transfer Protocol) supports various authentication mechanisms to secure email communication. These mechanisms include:

• PLAIN: PLAIN authentication sends the username and password in plaintext format. It is not considered very secure.
• LOGIN: LOGIN authentication is also a plaintext method where the username and password are base64 encoded.
• CRAM-MD5: CRAM-MD5 is a challenge-response authentication method where the client and server exchange responses based on a shared secret.
• SMTP-AUTH: SMTP-AUTH is a more secure authentication method that uses a username and password to authenticate the client.

It is important to configure SMTP servers with appropriate authentication mechanisms and encryption protocols to ensure secure email communication.