I use Civi 4.7.27 on Drupal.
When using the back-end form to register a contact to an event, and checking the 'Send Confirmation' checkbox, then the 'Receipt From' email address shown is not the one I want.
I tried to change the general Civi's default 'From Address' to the one that I want, but this did not affect this address.
Where is this email address defined to be the default one for sending registration confirmation emails from?
Clarification - when a user registers by himself using the online registration form, he does receive the confirmation email from the correct address, as it is defined in the 'Online Registration' tab of the event configuration page. The problem only happens for manual back-end registrations.