Interesting question, usually when people ask how a communist-adjacent world would work, it’s always ‘but what about prisons?’

On a small scale, I see people that want to take care of their community organize into groups to do all kinds of tasks, from cleaning the streets to delivering letters. With enough people and organization this system can be made efficient and flexible.

For longer distances, even in a solarpunk world there would be a need to move goods around the world, postal organizations might entrust their parcels to trains/ships going in the right direction.