My guess would be that if the wireless web access is limited in your country, then this would not work.
Running your own Calibre Content Server is one way to make your personal library available to you anywhere you have wireless access.
As far as international users with restricted web access, it could be that the Kindle global ISP is not blocking port 443. That's interesting. If that's the case, then an international user should be able to connect to secure web servers like gmail.
https://mail.google.com