Enhancement - Addresses are not checked for Validity

[neilmadsen]

Currently customer and Partner addresses are only checked for semantic validity (Did you put something like #### Name Street in the first Address field) and not actual validity (Does the address exist). Currently this is not going to be fixed but might if we have time.

This API might help if we decide to fix it.
https://tools.usps.com/go/ZipLookupAction!input.action