Hello Srinivasan,
Thank you for contacting the Delphix community.
The Audit log and the Event viewer should keep track of reboots with a timestamp. In regards to monitoring smtp email alerts can be setup for the Delphix Engine, see this document for more information:
https://docs.delphix.com/display/DOCS50/Email+%28SMTP%29+AlertsHowever, the Delphix Engine should not be rebooting unexpectedly. If you are experiencing unexpected reboots I would recommend opening a Support ticket and have the support staff investigate.
https://support.delphix.com/hc/en-us">https://support.delphix.com/hc/en-us">https://support.delphix.com/hc/en-usIf you have any further questions please let me know
Kind Regards
Adam Smith