Received a letter from local city police saying they have in possession an unidentified mail addressed to me, asking to come and pick it up, else it will be disposed of after 90 days. 1. Why my mail was given to police dept, instead of delivering to my home? 2. Why police writing a separate letter to me to come and pick up my mail from their office, instead of giving my mail to USPS, so USPS can deliver to my home? 3. What happens if don't pickup that mail ? How this situation (or event) will affect my immigration process. Thanks in advance.