IMO, this is the way to go. With the advances in TLS, I have done expts where you can use HTTP headers and server logs as "email" or short message service like Twitter. The "website" can be nothing but some plain text, or even just a 404. Heck, you can even skip a secure backend web server like djb's httpd and just use haproxy alone with option httpclose and no server directive. You can return the headers sent to the sender to simulate "posting'.

The US is now feeling the effects of having single websites with millions of pages. It was a stupid idea and is damaging to society. Super high scalability should only be for government websites and the like.