Magento – How to use USPS and UPS PHP API for getting tracking Information

I guess a simple solution is to edit the email template and add a tracking link:

http://nolp.dhl.de/nextt-online-public/set_identcodes.do?lang=de&zip=[ZIP]&idc=[TRACKINGNUMBER]

I used the following code in my ../template/checkout/onepage/shipping_method/available.phtml custom theme template inside the foreach shippingrategroups loop....

USPS and additional shipping methods must be enabled. It forces any APO address to USPS if it finds a city or region code that matches.

         <?php //Added to force USPS for APO
            $address = $this->getAddress();
            $apoStateCodes = array("AE", "AE", "AP");
            $apoCityCodes = array("APO", "FPO", "DPO");

            $regionCode = Mage::getModel('directory/region')->load($address->getRegionId())->getCode();

            $carrierName = strtoupper(str_replace(" ", "", $this->getCarrierName($code)));
            if (in_array($regionCode, $apoStateCodes) || in_array($address->getCity(), $apoCityCodes))
            {
                // IT IS APO, so skip iteration of non-USPS
                if ($carrierName != "USPS")
                {
                    continue;
                }
            }
            else
            {
                // ITS A NORMAL ADDRESS
                if ($carrierName == "USPS")
                {
                    continue;
                }
            }

            /* OLD WAY OF DOING THINGS (only works on PO box)
            if (preg_match("/p\.* *o\.* *box/i", $this->htmlEscape($this->getAddress()->getStreet(1))))
            {
                $carrierName = strtoupper(str_replace(" ", "", $this->getCarrierName($code)));
                if ($carrierName != "UNITEDSTATESPOSTALSERVICE")
                {
                    continue;
                }
            }
            */
         ?>