You can export your customer list to a CSV format by using the Export option on the Customer section of the Owner Dashboard.
Steps:
From the Owner Dashboard, click on Customers
Click the Export Button
Pick the timeframe and click Export:
Breakdown of the columns included in the export:
Name: Guest's first and last name
Email: Guest's email address
Phone: Guest's phone number
Created: Date when they were added
Last Order On: Last order date
Following Email: If TRUE, the guest has opted in to email marketing. If FALSE, the guest has opted out of email marketing
Following SMS: If TRUE, the guest has opted in to SMS marketing. If FALSE, the guest has opted out of SMS marketing
Points Used: Reward points used in the past
Points Remaining: Reward points balance