Shopify is integrated by default with Amazon, Shipwire, and Webgistix. I know from experience that it can be fairly easily integrated with other 3rd party logistics providers.
On a related note, I heartily recommend Shopify as an e-commerce platform.
Just setting up a shopify site. Had to do my first delivery (from a kickstarter) and courier messed quite a few things up, hence why I ask. Thanks for feedback.
