"網上還是隻有投遞送出的信息"? - 回複：求建議

What exactly does it say? Do you mean anything like following? - "Your item was delivered at 1:50 PM on June 4, 2007 in RANDOLPH, MA 02368. " Then it is good enough.

Although USPS is often called "United States Postpone Services", I would not take any action to refile petitions. Since you shipped it by Express mail, normally it is the one which would run into problem, the least.