In order to use Paypal you need to enter the following domain names as freely accessible:
www.paypal.com
api.paypal.com
api-aa.paypal.com
api-aa-3t.paypal.com
notify.paypal.com
www.paypalobjects.com
Trace: • Syces • Create/Edit Host • navigation_en • aruba_hidden • Host Module • Create/Edit Tariff • Release Notes • Voucher Module • Frontend • bintec
