To add a customer as a Contact in Matrix, go to the My Matrix tab and click Contacts. In the bottom left of the screen, click on the Add button:
The only required fields on the add contact screen are the first name, last name and email address fields:
You are welcome to fill in as much, or as little as you want. Click Save when you are finished.
Once the Contact has been added, Matrix automatically creates a Client Portal for them, which is where any future emails you send them will appear. They will also be able to run their own searches from within their Portal.