Below are the details for each fields when you first time install the module uspostal800v4:
Enable : Set Yes to enable US Postal realtime shipping.
Merchant User ID : Enter your USPS user id
Merchant Password : Enter your USPS password
Merchant ZIP Code : Enter your merchant zip code
Server Name : USPS production URL. Leave default to : http://production.shippingapis.com/ShippingAPI.dll
Ounce Field : USPS requires weight in pounds and ounces. You need to enter a field in the products table to place the ounces. Default field is pother4.
Pound Field : The default field for pounds is "weight". This can also be changed if needed. Pounds must be whole numbers.
Communication Interface : Communication Interface to UPS. Valid values are : XML2 / XML3 / XML4 / ASPTEAR / DYNUHTTP
For example, if your server only have XML2 installed, then enter XML2. You can ask your webhost for what xml components are installed in your server.
Individual Packages : Setting to Yes forces calculation of each product separately. This adds greatly to overhead since multiple calls to USPS are required.
Use Supplier ZIP : If you want the supplier to be used as the shipping address, set this to Yes. Works only in conjunction with Individual Packages=Yes.
Auto Separate Packages : Set to Yes to turn on auto separate packages features.
Auto Separate Weight : Set a weight value to use for auto separate packages. Example, if you set 150, if weight is greater than 150, then auto separate packages. Does not apply to individual packages.
Zero Weight Error : Set to Yes means it is an error if total weight is 0, Set to No means shipping cost=0. Default is Yes.
Check Individual Product : Set to Yes if individual product requires separate shipping calculation.
Individual Product Field : You need to enter a field in the products table to use for individual product checking. Default is pother3. Works only in conjuction with Check Individual Product = Yes.
Trace Mode : Set to Yes to see various phases of USPS calculation (debugging mode).
Language USPS Select : The text used in uspostalrealtime.asp page. Asking customers to select USPS shipping method. Default text is : Select USPS Shipping Method.
Language USPS Weight : The text used in uspostalrealtime.asp to show the total weight in USPS page. Default text is : Total Weight is.
Language Zero Weight : The text used in uspostalrealtime.asp when total weight is zero. Default text is : Packages have zero weight. USPS cannot determine shipping price.
Domestic Service Types : Enter USPS service names in separated commas that you want to use for domestic shipping. Default value : Express,Priority,Parcel,First Class.
Exclude Service Types : Enter USPS service names in separated commas that you want to exclude from USPS shipping methods.
Weight Units : The text used in uspostalrealtime.asp to show the total weight metrics.Default text is : lbs.