${cert_issuer}

Holds the distinguished name (DN) of the certification authority (CA), which is the certificate issuer. 

${cert_subject}

Holds the DN of the certificate that is called the cert subject.

${cn_issuer}

Holds the common name (CN) of the CA, which is the cert issuer.

${cn_subject}

Holds the CN of the certificate that is called the cert subject.

${tls_version}

Holds the version of TLS that is used for the connection. 

${cipher}

Holds a set of cryptographic algorithms (known as a cipher suite) that is used for the connection.

${cipher_bits}

Holds in bits the key length of the symmetric encryption algorithm that is used for the connection. 

${verify}

Holds the result of the verification of the certificate that was presented. Possible values are as follows: 

• OK – The verification succeeded.

• NO – No certificate was presented.

• NOT – No certificate was requested.

• FAIL – The certificate that was presented could not be verified.

• NONE – STARTTLS has not been performed.

• TEMP – Temporary error occurred.

• PROTOCOL – SMTP error occurred.

• SOFTWARE – STARTTLS handshake failed.

${server_name}

Holds the name of the server with the current outgoing SMTP connection. 

${server_addr}

Holds the address of the server with the current outgoing SMTP connection.