Symptoms

We got an error that if a task is assigned to a K2 role (or a user), the notification email is not generating.
We have already restarted K2 service but the issue is still present.
 
 

Diagnoses

Check the connectionStringEditor file's values of EWS and SMTP in the hostserverin
 

Resolution 


Opening the connection string editor and changing the SMTP connection to STARTLS , accompanied with username and password, then restarting the k2 service resolved the issue.