KB439292: 'Can't send command to SMTP host; nested exception is: javax.net.ssl.SSLHandshakeException

SYMPTOM
Subscriptions execution fails and the following error can be found in the DSSErrors.log:
 

Can't send command to SMTP host; nested exception is: javax.net.ssl.SSLHandshakeException
PKIX path validation failed: java.security.cert.CertPathValidatorException: timestamp check failed
java.security.cert.CertificateExpiredException: NotAfter: <Date:Time>

CAUSE
The SSL certificate on the SMTP server has expired, effective from the date and time seen in the error message.
ACTION
Update the SSL certificate stored on the SMTP server.
  KB439292