>
> the next best thing to a CASS db (as it comes directly from the USPS).

Sort of. The database is up-to-date and free, but they do a poor job of attempting to correct addresses that might not be entered correctly. Where a 3rd party product would correct an address, USPS will return an error. But good enough for most situations.

>do you remember where you saw the mentioning of that the USPS site is "...but are willing to let people do it"? it would be helpfull to have a reference for the future just in case they complain at a later point in time.


From the ZIP matching FAQ:


Can I process batches of ZIP+4® lookups such as an entire database-online?

The purpose of the ZIP+4 look-up system on our WWW server is to avail the public of a simple means of obtaining ZIP+4 Code information. The primary audience we seek to serve are customers who occasionally require ZIP+4 Codes.

ZIP+4 Lookup is intended for interactive use, not automated script processing. Although we do not intend to impose a limit on the number of inquiries we allow a customer to request in a given session. If we determine that our open-access policy is being abused or overburdened, we will have to review it. Regardless, we do not intend to offer batch processing capabilities via this service.

Customers who wish to perform batch processing should explore the following options:

Commercial Address-Matching Options
Address-Matching Software Development


Sounds like Don't-ask-don't-tell to me. It's useless for large batches anyway, so my type of use is certainly not going to burden their server.


>thank you for all your help.
>(i would give you some stars, but the chatter section does not allow them)

That's okay. I'll just draw some on my screen.