W3 total – leverage browser caching not working with cdn delivered images [closed]

Your expires value in your CDN settings is likely set to a low number. Your CDN expires header is overriding what is coming from your origin server which is why when you enabled the CDN, you received that message from Pingdom. Try increasing your CDN’s expires value.

Also if you’re searching for a reliable CDN service I would recommend giving KeyCDN a try.