From today, Poczta Polska will deliver registered mail to the mailbox

The changes introduced do not apply to parcels sent to or from courts, prosecutors' offices and other law enforcement agencies, as well as court bailiffs.
The coronavirus epidemic has forced changes in the provision of certain services. As a result of these changes, in states of emergency or in the event of an epidemic or epidemic threat, registered letters without acknowledgment of receipt and without Electronic Confirmation of Receipt (EPO) can be delivered to the recipient's mailbox without the need for a special request. The requirement for couriers to obtain a receipt for the shipment has also been suspended.