Sylvia Kneller, who suffers from arthritis and heart problems, first started responding to the fraudsters when she was 20 years old and says she became "a believer", convinced she would one day win a fortune.
But now the pensioner, whose first husband left her over her refusal to stop responding to the letters, has spoken of the impact on her life in a bid to warn others who have become addicted to the scams.
She said: "All the mail that I have been getting I realised was spam mail, spam letters but it does get you all excited and they shouldn't do that to old people, it's not right, not nice at all.
"But anyway, I have been doing it since I was 20 and I am now 76 and the amount of money, £200,000, is what I have spent out thinking that I was going to win, to get money back but I never got a penny, I can honestly say I have never had one penny from them.
"But in your mind, if you are a believer, you believe it and that's it and other people start on at you and you know they are right but you still believe, you still want to do it, it becomes like an addiction really.
"My first husband, we parted company over it because he was fed up with it and anyway he ended up with my best friend.
"I thought I shan't send any more money since the lady came out from the council's trading standards and I am grateful for that. I do not send money out now because I can't afford it. If I had kept my money in my purse I would have been rich."
The letters received by Ms Kneller, of Farnham, Surrey, included claims that she had won large sums of money but she needed to send processing fees of £20 for her to claim the prize.
Steve Playle, investigations manager for Surrey County Council Trading Standards, said: "This is the worst case we have come across but I wouldn't be surprised if there were worst out there that we haven't come across yet.
"There are a very small proportion of the population who do respond to these spam letters and they are a bit forgotten about.
"We want to encourage people to speak to their elderly neighbours and friends and if they are receiving these types of mail, to make sure they are not responding to them and to point out they are not going to get any money, they are just lining the pockets of fraudsters."
Mr Playle said he had been shocked at the amount of money some people had paid out and his team was looking into the cases of 80 people who had repeatedly fallen for the scams.
He said: "Sometimes people are quite lonely, it's their only contact with the outside world, they do feel addicted and I know people find it hard to understand.
"Sylvia is one of those people and it's quite brave of her to come forward and be highlighted as a victim to warn others."