To extract customer data from e-Res, select the "Extras" tab at the top of the screen and select the "Export Customers" option.
This will open up the "Customer Export" screen where you can select to export all customers, or only those with e-mail addresses.
Once you've made your selection, click on the "Export" button and you will be prompted for a location to save the CSV file.
Choose an export filename
Select the folder you wish to export to and click "Save". You should now see a CSV file containing your data in that location.