Sending different Mails when customer orders different items


we’re using Mautic with our E-Commerce systems. Currently we create a contact in Mautic via REST, when an order comes into our shipping software.

BUT: If the email already exists in Mautic, we’re not importing the contact again.

So, when a customer ordered a 2nd time, a 2nd product, how can we tell Mautic about that, so that a 2nd Mail Campaign is being triggered/the customer moves into a 2nd Segment?