Mail sending sending/delivery fails with '' in EngageOne Digital Delivery


EngageOne Digital Delivery fails to send mails. Following exception gets logged in the EngageOne Digital Delivery application logs:

javax.mail.MessagingException: Can't send command to SMTP host;  nested exception is: PKIX path building failed: der.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target  at com.sun.mail.smtp.SMTPTransport.sendCommand(


This could be caused in a situation when EngageOne Digital Delivery tries to connect to SMTP server using 'starttls' however SMTP does not support it.


UPDATED: July 17, 2017

EngageOne Digital Delivery assumes that SMTP server is 'starttls' enabled. In case there is a need of connecting to a SMTP server using non starttls connection, follow these steps:

  • In (Located in '\core.war\WEB-INF\classes' directory) file change the value of 'mail.smtp.starttls.enable' to 'false'. By default, value of 'mail.smtp.starttls.enable' is set to 'true'.
  • Restart Application Server on which EngageOne Digital Delivery is deployed.