Symptoms
Default Client Event Failed sending Notification
Diagnoses
Issue:-
Unable to receive client event notifications:
No destinations could send the message
Resolution
1. Kindly check that the email indicated on Exchange configuration is associated with a local AD account
http://help.k2.com/onlinehelp/k2blackpearl/icg/4.6.8/webframe.html_exchange_server_configuration.html
2. Also check if the K2HostServer.exe.config file has this line filled in with the correct smartactions account
If not, kindly make the changes and restart the service.