後來搬過家，是在郵局改過地址（4年前了）
-Unless you asked USCIS to update your address in their system, all the USCIS mails will be sent to the old address and then, wil be retured back to USCIS.
，不知道這種情況是否會把信退回給uscis，
-Yes.
但根據tracking number的信息，郵件是delivered. 太奇怪了。
-Maybe someone in your old address received it and signed the confirmation.
