Unless an appliance is permanently connected to the power/water supply (like a stove or a plumbed in refrigerator) then it is not included in the contract unless listed under the "inclusions" section.
Dont take the RE agent's word for it, list it. Dishwashers and washing machines are attached to the plumbing but removable, so not incuded unless specifically listed on the contract.
Curtains and blinds can be a "grey area" so we always include them in the contract when purchasing, also those removable clotheslines. We have never gone as far as listing the letterbox, though we have heard of one case where the vendors took it with them!!
We sold a unit last year and the dryer was not listed under inclusions as we expected. It was only 6 months old so we kept it.
Marg