It is really confusing how CookieContainer handles domain.
According to RFC 2109 when we set a cookie to domain ".site.com" the CookieContainer does not send the cookie to the domain.
Receiving the cookie from www.site.com and site.com both are expected. But nothing will be sent!
I believe it is a bug!
I have searched a lot about this issue and I found some hacks to pass through this, but still it don't work properly: