Form googlemail directly? I can not believe that.. Who in their right mind would do that?
There are other options: "Google Toolbar", Chrome.. but it does not matter.
Google indexes stuff that people publish, it does not do black magic.
Google know about 1560 URLs (by screenshot)
For safety reasons, he showed you only the first 170, but there are other ways to get those links.
But the problem is not in Google. The problem is that even Google can find a lot of URLs.