No, your tenants can not with hold rent for missing laundry and packages. They can stay with their laundry and they can report missing packages to the post office or UPS, which ever. When your tenants do with hold rent, serve them immediately with a Pay or Quit notice followed quickly with an eviction action. Just flat out tell them that they will be swiftly evicted for nonpayment of rent. And, do not back up.