美国快递跟踪链接

DHL
http://www.dhl.com/content/g0/en/express/tracking.shtml?brand=DHL&AWB={tracking_number}
Fedex
http://www.fedex.com/Tracking?action=track&tracknumbers={tracking_number}
UPS
http://wwwapps.ups.com/WebTracking/track?track=yes&trackNums={tracking_number}
If any value is provided for the “track” parameter then the confirmation page is skipped and the user goes directly to the tracking page. If you’d rather send the user to the confirmation page then just omit that parameter.
USPS
http://trkcnfrm1.smi.usps.com/PTSInternetWeb/InterLabelInquiry.do?origTrackNum={tracking_number}