This feature is NOT available since our 2.7.0 release!
It’s possible to speed up your website by using Cloud Computing Services.
You just need an account on Amazon S3 and then log into your admin panel and select Settings -> Images. Scroll down and you will find the Amazon S3 Configuration section. Insert your AWS Access Key, AWS Secret Key and Amazon S3 Bucket Name, select your S3 Domain Name and don’t forget to press SAVE.
Warning: Using Amazon Simple Storage Service is NOT for free! Amazon S3 Pricing