If the package is express it can be setup to waiver signing for and thus no ID required. I've never been asked for an ID ever at a post office. I've had to fill out paper work but never has ID been required you dont have to sign you real name just any name or scribble of a name will do. I've used post offices to ship stuff of this nature for damn near a decade and I've never had any issues with me walking right through the front door with a package full of contraband, know I do not suggest anyone without experience march into post office with illegal packages for shipping just saying 90% of my shipping is done in person with various PO in total about 6 a frequent on a monthly basis.