To configure TLS security mode for situations when Kaspersky Secure Mail Gateway receives messages from another server (acts in the Server role):
In this case, Kaspersky Secure Mail Gateway receives all messages in unencrypted form.
In this case, Kaspersky Secure Mail Gateway uses the STARTTLS
command to offer the server that sends email messages to use TLS encryption, but accepts messages regardless of the server's response.
In this case, the server that is sending email messages (Client) uses the STARTTLS
command to offer Kaspersky Secure Mail Gateway to use TLS encryption. Kaspersky Secure Mail Gateway responds with the STARTTLS
command and sends the Server certificate to the Client and also requires the Client to verify the authenticity of the Server certificate. The encrypted TLS connection is established after the Client has verified the authenticity of the Server certificate.
You can create or import a TLS certificate in the Encryption keys section, TLS subsection of the main window of the Kaspersky Secure Mail Gateway web interface.
Set the Request or Require mode only if you are certain that the clients supported by your mail server can provide a verifiable TLS certificate.