I have a medical condition that prevents me from wearing a mask. Refusal of service based on this is a clear violation of human rights. There is a full physical barrier between the postmistress and the customer, and there was no one else in the building. Banning any individual from service or entry is a dangerous precedent. Treating any human being badly because your authorities told you to is a complete replication of historical atrocities that we all are repulsed by.