No we did not do that, there will hopefully be push notification soon though. We have kept this as much a skeleton tutorial as possible. IMHO this is 90% of the way to email MVP all it needs is a couple of libs for layout, reply linked (just a route) and some tweaks.
So secure, private, not going through any servers, I think this could be something, now I wonder what the next few examples will show off 
@lightyear is in secret hole starting on one that may surprise a lot of people as well.
Waited so long for folk to see this is not a storage network and these examples/tutorials will allow the app devs on this forum and beyond to take them and show off amazingly good easy secure free privacy enhancing apps and it’s about time we got here. Ofc more to do in back end (vaults) but hope you will see front end capabilities starting to become very powerful.