> Battery life Would it be any more battery life consuming than having an always on connection for push notifications? I used to have a local http/ftp file server running on my Nokia N9/N900 and even on my early Android phones back in the day. I used to still get an all day battery life.

> Imagine losing an email because you walked into the subway and your phone was unreachable the moment an SMTP server tried to connect to it.

Dont SMTP servers already retry a few times before giving up? Plus it is not like you're using the phone to host content for the whole of the internet. It would be just for your close circle usually.

I am not saying phones make the perfect servers for all kind of applications but for certain kind of workflows... I think Phones are pretty good. Our network infrastructure (NAT, firewalls etc... limited data plans etc..) is the main headache for most of these use cases. But the network infrastructure is a problem even for our laptops, home computers etc..