Door-to-door sellers are working in Snape today (Thursday 6th August). It has been reported and is being actioned. It is not illegal to sell at the doorstep, but homeowners often feel pressured into purchasing something just to make the seller go away. You do not have to purchase and they should leave when asked to do so.
You do not have to purchase anything and can find out more on the Suffolk County Council website at - https://www.suffolk.gov.uk/community-and-safety/suffolk-trading-standards/fair-trading/rogue-traders/
Always be aware of scams and scammers.