Trash requires the Add-On for this mod, Mail & Waste.

In order for buildings to produce those new commodities, their input must be satisfied first. For example, you would first need to deliver either Fuel, Machines, or Construction Material to the Industrial district in order for those buildings to produce Waste.

Same thing applies to the Commercial district with Mail. Once you start getting a Mail chain going, you can deliver them to the Residential district and some of those buildings will start sending Mail out as well.

How do I get mail I cant get mail the addon isnt working right