Hello, I'm about to send my I-751 application but I'm a little confused by the mailing address. According to the USCIS website, I should send it to: USCIS Vermont Service Center 75 Lower Welden St. P.O. Box 200 St. Albans, VT 05479-0001 There is a POBox, and I recall that FedEx can't send packages to PO Box addresses. So how does this work? Can I use the USPS service only then? were your packages delivered via FedEx to the above mentioned address? Thank you and have a wonderful new year!