Example of how to set up STARTTLS (sending email)

[subornaakter20]

STARTTLS is configured by adding it to the configuration file of the "MTA" (mail transfer agent) used on the mail server, such as Sendmail, Exim, or Postfix. Note that the configuration content differs depending on the MTA, version, and OS being used, so be sure to check the configuration method for your environment before proceeding.

Example: If the MTA is "Postfix"

[Command]
vi /etc/postfix/main.cf

[Contents to be added]
smtp_tls_security_level = may
smtp_tls_loglevel = 1
smtp_tls_CAfile = /etc/pki/tls/cert.pem

[Command]
systemctl restart postfix



Difference between STARTTLS and SMTPS
Like STARTTLS, SMTPS is a mechanism medical mail list for encrypting email communication paths. With SMTP, the communication content is not encrypted when sending email, and is sent in plain text, but by using SMTPS, the communication content can be encrypted and email can be delivered. While SMTPS encrypts communication from start to finish, STARTTLS does not encrypt communication from start to finish, and whether or not to encrypt the communication from start to finish is determined by the receiving environment.

SMTPS is more secure, but if the receiving side does not support SMTPS, the email may not be delivered, so care must be taken. Also, STARTTLS does not require a dedicated port number, but SMTPS requires the use of a dedicated port (generally 465).