后来搬过家，是在邮局改过地址（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.
，不知道这种情况是否会把信退回给uscis，
-Yes.
但根据tracking number的信息，邮件是delivered. 太奇怪了。
-Maybe someone in your old address received it and signed the confirmation.
