It's my opinion that the Losties were not brought to the Island by chance, that there was some kind of force at work to make them all come together in that place at that time.

Based on that, I'm very certain that the Others do have contact with the outside world, and that they don't care about getting the Losties rescued, because that would draw even more attention to a place that they are very happy to have "unseen".

They want the Losties there for a reason, and it doesn't involve them all getting out of this alive!