Azure virtual network service endpoint policies enable you to prevent unauthorized access to Azure service resources from your virtual network. You can now allow access to only specific Azure service resources (for example, Azure Storage accounts), by using endpoint policies, over service endpoints.
Virtual network service endpoint policies provide more granular control for Azure service traffic from your virtual networks, in combination with the Network Security Group (NSG) service tags, for Azure services.
The feature is available in preview, for Azure Storage, in West Central US and West US2.