As you might be aware, USPS has recently updated their APIs, and as such Business Catalyst plans to upgrade to the latest version of the USPS APIs by July 29th 2015. With this new version, USPS requires merchants to provide product dimensions and weight for products shipped internationally.
As a result, if you are shipping your products internationally, please update all your sites that use the USPS shipping integration to feature package dimensions on all products. If you only ship within the US no action needs to be taken. If products do not have product dimensions and weight defined, the USPS API will return an error upon placing an order.
A detailed e-mail containing the sites that need updating will be sent to your inbox shortly.
Please update your site accordingly to take this matter into account. If you have any other questions regarding this subject you can check out the USPS migration technical note.