Mark the envelope and the cover letter with the type of submission. For example, Original Submission, Application to Register Permanent Residence or Adjust Status (Form I-485). Mark the envelope and the cover letter with the form number.
You may send your forms through USPS, FedEx, DHL, or UPS. We encourage you to save a copy of your payment, along with any tracking number provided by the courier, for your records and so you can verify the status of its delivery.