In order to ensure that CR-Certify is able to send emails on your behalf, an Account Associate must be selected. The dropdown for the Account Associate field is populated with all Staff Users and Staff+ Users with access to the section of CR-Certify administered by your company. 

For Projects and Subprojects, the emails can still send as long as there is an Account Associate selected at the Client level. This field "cascades" down to all Projects and Subprojects beneath a Client, and is only interrupted if a manual choice has been made at a lower level. If a manual choice is made at a lower level, then that in turn will also "cascade" down to all Subprojects beneath the entity where that manual choice has been made. You can tell if there is a cascading user for the Account Associate field by the informational message that appears when it is cascading downwards.