Woocommerce-How to find if email id has palced order before?

I am trying to make WP plugin for coupon system. When customer will place order second time i have to give the discount coupon to customer but coupon should only show when customer has already placed one order before.

Now i just want to search from orders , if specific customer already placed order by email_id.

I found one way: WooCommerce Get Item Meta from All Orders

but that way is little bit complicated and make my process slow, tell me if there is any another way. Thanks

via Chebli Mohamed