All that would have to be done is a additional account be added to the Zoho Mail and that account would be set up to forward all emails to the system generated email address for the receipt inbox. I know this works i did it on my mail server before going to zoho one. And now i cant do it with out creating a additional license on zoho one.

Why? Well the inbox is essentially a AR@yourdomain email that way all incoming invoices goes to it. Only issue is if someone emails that account that is not a receipt. So what could be done for that is all emails not only get forwarded to the receipt inbox but also a licensed zoho user.

This would automate the process while not giving some one a super long email to send invoices to.