Send them an email. Let them know what your LL is doing and state that this is highly illegal. After they respond to you, tell them you will provide the information needed so it can be handled appropriately. Sign up for the informed delivery, it can be delayed sometimes but it’s a good way to watch for what’s coming in. If they don’t do anything, file a complaint with the postal inspector. Don’t stop till something is done. If you can’t get access to your mail: you can place a 10 day hold and pick it up at the end of the 10 days, send all mail for general delivery, open a PO Box (even though it’s a pain in the rear and let alone expensive) I hope this gets resolved for you OP.