急！我前幾天寄出的I-751的申請表，今天在usps的網上查他的狀態，

結果說We attempted to deliver your item at 2:49 PM on March 19, 2008 in MESQUITE, TX 75185 and a notice was left. It can be redelivered or picked up at the Post Office. If the item is unclaimed, it will be returned to the sender. Information, if available, is updated every evening. Please check again later.

怎麽會這樣？TSC PO BOX為啥不能接受郵件？？TSC的人會去PICKUP嗎？如果每人去取，真的會退回來嗎？急死了。