The Click2Mail XML Ruby SDK by Click2Mail wraps the API to access mailing, shipping, and printing features. With interface communication, developers will be able to submit a mailing and submit an order by using the API.
Who needs a tracking service when you can just hop on the USPS, FedEx, UPS, or DHL website (or whoever your carrier is) and just track? Maybe you. The Trackthis API integrates an amazing array of functions into your application. The API webpage lists over 10 carriers you can get notifications for.