When we send an email on behalf of a shared mailbox, the emails comes as "firstname lastname on behalf of sharedmailboxname". In this case, the customer/receiver sometimes figures out the email address of the user himself and sends that user email instead of replying to the original email (since our email address policy is firstname.lastname@example.org).
My questions is that, is there any way, I can remove the last name from this design ? Only the first name shows when a user sends email on behalf of a shared mailbox ? We do not allow users 'Send As' permissions to shared mailboxes and they can only use the 'Send on Behalf of' permissions.