Symptoms

How to set alternate From Address for emails which are being sent from Default Client Event? I.e. when you need it to be different that address of K2 device account.

You have changed FromAddress value in Environment Library, in process string table, and sendmailfrom value in K2HostServer.exe.config file and restarted K2 service. Change reflected for Email Events but not for Default Client Events. Emails from Default Client Events still sending from K2 service account email address.
 

Diagnoses

At the moment K2 does not allow for the "From Address" to be configured in Default Client Events. There are number of open feature requests for exposing "From Address" in email wizards to make it more configurable (internal IDs: 374338, 541738, 651451).
 

Resolution

There is no options to set alternate From Address for Default Client Events in current versions of K2. Please log a support ticket in case you have strong interest in seing this feature implemented.