I don't see a direct way to do it - but one of the Square Staff might have a way.
Here's a work around though in case there isnt:
Through your Email address, set up Email Forwarding based on a Filter that only forwards the Inventory Alert Emails. It would keep the original email in the original email account inbox, but also foward a copy of it to the secondary email address.
Gmail makes it pretty easy to do this, if you happen to have a Gmail account, but it should be available with basically all email clients.
