Every branch could have their own type of notices, and have their own person to handle those notices. It doesn't make sense to have all the notices default to the koha administrator email address. Add "Message Sent By:" email address to the notice building screen, default to the koha administrator if it is left blank.
In recent configurations of setting up Email, I discovered it was working correctly, but GMail was re-writing the header, because I had not authenticated the other email addresses. Log in at gmail, and then go to the following in the address bar: https://mail.google.com/mail/u/0/#settings/accounts (cog -> settings -> accounts if you wish to click the long way)