Can I use Priority to mail application to USCIS

Why the delivery status shows

We attempted to deliver your item at 1:18 PM on December 7, 2006 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.

I didn't use signature confirmation service. How come to get this status???

所有跟帖： 

• 回複：Can I use Priority to mail application to USCIS -mortgage.ca- ♀ (44 bytes) () 12/07/2006 postreply 19:17:59

• 回複：回複：Can I use Priority to mail application to USCIS -pdan31- ♂ (36 bytes) () 12/07/2006 postreply 20:07:00

• 回複：回複：回複：Can I use Priority to mail application to USCI -mortgage.ca- ♀ (179 bytes) () 12/07/2006 postreply 23:12:53

• 回複：回複：回複：回複：Can I use Priority to mail application t -pdan31- ♂ (28 bytes) () 12/07/2006 postreply 23:18:32

• co-ask: If they can not sign for it, will it be returned? -wujw- ♂ (0 bytes) () 12/08/2006 postreply 04:55:17

• 回複：Can I use Priority to mail application to USCIS -紫石頭- ♀ (52 bytes) () 12/08/2006 postreply 08:56:49