Symptoms

When SmartActions is enabled, the Email event and Client Event emails are coming from different addresses, the "From Address" is grayed out in the client event notification wizard
 

Diagnoses

When using the SmartActions emails, we disable the ability to change the From Address in client event emails. This is so that when a user replies to the notification with a SmartAction, it goes to the correct mailbox and gets processed.

The "From Address" value for the Email event comes from the environment library.
 

Resolution

If you need to update the SmartActions email, you can do so in the K2HostServer.exe.config file. Locate the line containing
Note: after making any changes to the K2Hostserver.exe.config file, you will need to restart the K2 service for the changes to take effect.