The customer statements section can be found in the left hand menu under "Finances>Customer Statements".

Once you're on the customer statement page, use the filters at the top to find the list of statements for the desired customer you'd like to send to. You can filter by date, customer name, show payments only, invoices only, or show all.

After filtering and you have your customers statement list up, click the "Send Email" button at the top right hand corner of the page. This will bring up a pop up version of our email builder with the customer statement attached to the email. 

Add a template and customize your email, then click "Send Email" to finish.