Easy Image Optimizer (ExactDN) and Amazon S3
The Easy Image Optimizer service can operate automatically with images stored in an S3 bucket.
Both virtual-hosted and path-style rewriting is supported:
Note that Amazon is removing support for path-style URLs unless your bucket name contains a period (.). As such, you should use the first (virtual-hosted) style for most cases.
All region-specific domains, like s3-us-west-2.amazonaws.com will also work properly with Easy IO.
Automatic configuration is fully supported with WP Offload Media, if you use a different S3 plugin, you will need to manually configure the "local" domain, like so:
define( 'EXACTDN_LOCAL_DOMAIN', 'https://bucket-name.s3.amazonaws.com/' );
The preview URL shown by the WP Offload Media plugin contains non-breaking dashes that are invalid URL characters. You can, instead, find the proper S3 URL in the Easy IO settings (where it says "add your Site URL.." Alternatively, you may type the URL in manually, and it will work just fine (or copy the necessary portion from one of your actual image URLs).
CDN delivery should not be enabled in WP Offload Media (or any other S3/Cloud Storage plugin), since Easy IO itself is a CDN. The delivery method within your S3 plugin should always be pulling images directly from S3, and Easy IO will take care of updating the URLs from there.