Why won't my address verify / validate? - Smarty

USPS doesn't recognize my address!For an address to be valid, it must match a corresponding address in the official USPS address databasewhich can be accessed through the USPS APIs. If anaddress contains any incorrect data, it will not match a corresponding address in that database, and istherefore "invalid". Sometimes, an address will not validate because the address is marked as "vacant" by theUSPS. Additionally, a new address, an unregistered address, or one located within a postal code primarilyserviced by PO boxes, would all fail to validate. The best way to be sure an address is valid is to verify the address before you mail or ship something.Table of contents:How to perform address validationBad addressesHow do I get the USPS to recognize my address"But UPS delivered there; That means it's valid,right?"What do I do when an address is invalid?ConclusionHow to perform address validation: A detailed guideSome addresses won't verify because, for one cause or another, they're invalid...