First of all, treat all deliveries as if they might be contaminated. Secondly, take precautions before handling your envelopes or delivery boxes. According to research by NIH, coronavirus may remain on paper surfaces to up to 72 hours and therefore, you may want to let your packages to sit outside for that period of time before touching them. The same applies to paper currency. Either avoid using it or let it sit undisturbed for 72 hours before you handle it.