Apply for a Mailbox Download Form 1583 Please download, complete, sign, and have your Form 1583 notarized. You can upload your completed form below. Click here to download the form. Complete Online Application Complete the online application below. You will need to scan and upload images of your photo ID. Get Your Mailbox SwiftLink will review everything and get you a key to your private mailbox. Online Form – SwiftLink Physical Mailbox Signup