+Transport Layer Security (TLS) provides certificate-based
+authentication and encrypted sessions. An encrypted session protects
+the information that is transmitted with SMTP mail. When you activate
+TLS, {pmg} automatically generates a new self signed
+certificate for you (`/etc/pmg/pmg-tls.pem`).
+
+{pmg} uses opportunistic TLS encryption. The SMTP transaction is
+encrypted if the 'STARTTLS' ESMTP feature is supported by the remote
+server. Otherwise, messages are sent in the clear.
+
+Enable TLS logging::
+
+To get additional information about SMTP TLS activity you can enable
+TLS logging. That way information about TLS sessions and used
+certificate’s is logged via syslog.
+
+Add TLS received header::
+
+Set this option to include information about the protocol and cipher
+used as well as the client and issuer CommonName into the "Received:"
+message header.
+