Symptoms

"There is no connection string for the destination email address System@K2.local" error on email event
 

Diagnoses

Initially, there were no connection strings decrypted within the K2HostServer.exe.config file. After running a repair on blackpearl, the connection strings have been restored but the issue with the email event persists.
 

Resolution

After changing the authentication type from Anonymous to Windows using the Connection String Editor, email events began to work normally