>Hello everybody.
>
>In my app i want to provide a 'soft' address verification. what i mean with soft - its more of a recomandation rather then 'must be this way or the highway'.

There is no good way to verify an address without a CASS directory. Since addresses can often parse in more than one way, it's difficult to attempt to parse without a check against a CASS database. Without having the directory of valid addresses, all you can really do is really the most rudimentary check for 5 or 10 digit zip, etc. Maybe make sure the street suffix is contained in a valid list.

There are a few companies which sell address objects which allow you to parse and CASS an address. I use one by Mailer's Software. I think it was about $200 several years ago. But to CASS the address you also need a subscription to the CASS database, which must be kept up-to-date. Some companies also offer an online subscription where you process online and pay on a per-record basis. You can still use the address object to parse addresses without the CASS subscription, but you won't be able to append zip+4.

What I do is use a combination of the address object to parse the address and then also have a routine which passes the address to the USPS site to CASS the address or get an error code. This isn't fast or the most accurate CASS method, but it's good enough for a free solution. All I really need at that point is the validation and the +4 for geocoding.