Recommendations from the meeting will be presented to the DMA board in January next year, where they will be formalised and potentially integrated into the DMA Code of Practice.
Rosemary Smith, chairman of the DMA, said: "To safeguard both the direct marketing industry and the environment, we need to focus on a real change in behaviour.
"We want to stimulate a quantum shift in member, industry and wider business understanding of the importance of environmental issues.
"Not acting is not an option -- it is imperative we future proof our industry and we hope this environmental manifesto will go some way to leading a change."
The DMA has already made investments into creating a series of measures that aim to minimise waste and reduce the impact of the industry on the environment.
It has a partnership with Envirowise and Friends of the Earth to develop a series of sector specific "enviro-guides", which will enable members to work to a set of guidelines to reduce their environmental impact.
The DMA also has a partnership with Wrap to allow its members to use a variety of logos from the "Recycle now" campaign.