Trading Standards officers are warning Barnsley residents of the dangers of responding to scam mail.
Barnsley's Trading Standards officers have found 350 names of people from the town who have responded to scam mail prize draws and lotteries.
Now they are visiting residents on the list to provide advice about how to avoid further scams, and to collect information on the scam mail companies who targeted them.
Coun Roy Miller, a Barnsley Council cabinet member, said: “Scams like these target vulnerable groups and one of our main priorities is to protect the vulnerable.
"The people sending these letters are organised criminals who only want to gain bank details or persuade you to send them money for prizes that don’t exist.
"Unfortunately we know that the companies involved in these scam mail frauds have 'suckers lists'. They exchange information regarding people that they know will respond to mail and this creates a bombardment of scam mail through victims letter boxes.
"If you receive a temping letter in the post remember ‘if it looks too good to be true, then it probably is'.
"If you feel that you have been a victim of scam mail, or know someone who may be, you can report this to Barnsley Trading Standards through the Citizens Advice Consumer Service Helpline."
Call 08454 040506.