We got one of those letters once as well from Belgium. Said they had been looking for relatives blah blah blah. Funny thing is when my grandfather came here after WWII his Russian surname was mis-translated by the Germans. The only people with the name are relatives we have in Australia. Our name is unique and doesn't exist anywhere else in the world. So I don't know what relative they are talking about  Anyway got a Belgium stamp for the kids stamp collection