Yes I have read this but its very unclear, especially when you want to write a provider for Outlook so, maybe you know of a normal tutorial on how to do this, or similar?
I'm guessing, after staring for 4-5hours at MSDN code I could achieve enlightenment...
I just found an old article on MSDN about the whole topic. It's not that helpful and does not provide full samples. But the author actually wrote a book about that topic. They even provide lengthy examples which are available as public download. You can find the implementation of a custom sync provider inside the archive at "\Pro Sync Framework\Chapter III\Code\CustomProvider\CustomProvider.sln".