The homeless can receive mail. General Delivery, mail addressed to them care-of some charity organization or shelter, any family or friend. Mail forwarding is

The homeless can receive mail. General Delivery, mail addressed to them care-of some charity organization or shelter, any family or friend. Mail forwarding is a thing for those who move, although TBH it would be prudent to use the "Do not forward" option on this, as mail forwarding itself is prone to fraudulent usage. I guess if you've moved, you would need to mail them proof that you lived at the old address and that you live at the new address. I had to do that to claim unclaimed property with the state -- I had to send them some old bills or legal documents showing the old and new addresses.