If you put that you ‘always try to respond to emails within 1 working day’ on your website, it could be argued that you’re creating a reasonable expectation that this will happen.
Even if you miss your 1 day aim, the customer would be expecting a reply of some kind within a couple of days or three at the most, and would definitely be feeling somewhat ignored by five, regardless of what Trading Standards say.
I notice your other thread on emotional responses. I don’t think the OP’s initial response here was entirely over-emotional and unreasonable.
Obviously he didn’t understand the ombudsman system, but lack of contact left him feeling powerless, and I can see how that can provoke an emotional response.
The essence of good customer service in online shopping (because there is no face-to-face element to build trust) is swift communication. Even if it’s just a standard email saying that the problem will take a while days to sort out, so bear with us. If firms raise false expectations in customers, then this is a fairly inevitable consequence.
Trading standards may have a view on what is reasonable, but that is way out of kilter with my expectations as a customer, and I’d be wary about using it as an example of good practice.
A holding email of the type I’ve described takes seconds to produce – if any company gave me two weeks of blank screen in response to a email I wouldn’t use them again.