The Sustainability Tracker study commissioned by the Direct Marketing Association (DMA), fast.map and Onepost found that more than two thirds of respondents thought email had the least environmental impact.

The recycle logo was perceived as the most recognisable marque denoting environmental responsibility of the company involved, followed by the type of products being advertised and media coverage.

However, head of postal affairs Alex Walsh said that recognisable as it is, many consumers remain unsure whether it means the product is made of recycled material or is itself recyclable.

Equally, respondents said that they would feel negative in regards to a company associated with marketing materials using windowed envelopes or polythene wrapped.

"We often take the view that consumers have a greater understanding than they actually do," said Walsh. "Everyone thinks that everything physical, tangible, things that you can touch ends up as waste, and that something that you can't is not waste.

"The facts aren't anywhere near as clear cut as consumers perceive. For instance recent studies have shown that data centres account for nearly 2% of energy use, the equivalent of the aviation industry, while another suggests that paper may be the only truly sustainable communication medium."

He said that despite the marketing sector specialising in messaging and communication "sometimes we're not very good at telling people what we're doing".

He said that bodies such as Two Sides have "a big role to play".