For most international mail orders, you can track your order here: www.ppxtrack.com/t/healthdesigns/
You will need to input your tracking number, which can be found in "My account"
Some countries provide further tracking of the package once it is inside your country's postal system. In that case, you can take the USPS Tracking # and track further on your local postal website.
For example, lets look at this tracking: http://www.ppxtrack.com/t/healthdesigns/RRD020738500067466
For further information, we will copy the USPS Tracking #: LM852135124US
Then, go to the local post website, in this case Brazil, so Correios. When we track the package on the Coerrios website using the USPS Tracking #, we see the following detail:
While this shipping method is not guaranteed to offer tracking, it does occasionally provide updates on where your order is.