It was set in the England during the early 19th century, and dealt with a secret love affair between a man and woman - for some reason their affair had to be a secret.
The woman had a friend of a young local boy who would carry her love notes and messages to the man, but the boy got jealous of the relationship and I think betrayed their secret. I can't work out if Oliver Reed was in the movie, if it was Women In Love, or some film based on a Thomas Hardy novel.
It was definitely a British film - Can anyone help? It's wrecking my head!
Thanks everyone for your reply - Cyanide - I think your right, the image I have in mind of the actress is I'm sure a young Julie Christie and my sister too loved this film and taped it and watched it regularly. It was actually set I think in the late 19 century and not the early 19th century as I originally posted.