I have checked multiple sources and all my records show that this address is correct. Why then is your system "correcting" these addresses to different ones?
3500 Chambers Road, McAlester, OK 74501
563 W Chambers Rd McAlester OK 74501-2287
This input address has been confirmed by the recipient as a good address so this makes no sense at all. I've tried the input address 10 different ways and it happens each time.
RR 1 BOX 194 SAN AUGUSTINE, TX 75972-3619
2744 FM 1279 SAN AUGUSTINE, TX 75972-3619
Typically, the USPS is the authority on addresses. They determine which addresses they will deliver to and they also determine which ZIP Code a certain address pertains to based on the delivery route. So, there are multiple reasons why an address might be corrected to something other than the expected address.
The LACSLink database was created in an effort to convert rural-style (rural route, or RR) addresses to city-style addresses (addresses with actual locations instead of just boxes). LACS stands for Locatable Address Conversion System.
It began with the implementation of the national 911 emergency service address database. The USPS is attempting to phase out the RR addresses in favor of actual physical addresses.
In the example above, the RR 1 Box 194 is a delivery unit (or box) while the 2744 FM 1279 address is an actual physical address. You can mail to either location and your item will get there.
The Postal Service linked their database with the national 911 emergency directory so that emergency service providers such as fire trucks and ambulances can find the address associated with a phone number. If 911 gets a call from a phone number that is registered to RR 1 Box 194, they can't actually find someone at that location, but if they drive to 2744 FM 1279, they'll be able to help the person that made the call.
In the case of the addresses above, the reason another address comes back is that it has been matched to a physical address in the LACSLink database. The address has been converted to an accurate street address.