Offtopic from Sandstorm but on the topic of personal servers it would be good if somehow an email server could also respond to requests as a web server in some way. Or maybe respond to particular inbound emails as HTTP requests. Sort of makes sense since the server that your email address lives at is kind of your "home on the web".
You could configure your email then perhaps to respond with things like your personal profile, in response to anonymous inbound requests.
That's something that should be possible in a Sandstorm app, if you want to make it do that. (-:
To do it securely in Sandstorm would have to wait for our secure inter-app communication system, similar to Android intents, called the Powerbox. But we're working on it.
You could configure your email then perhaps to respond with things like your personal profile, in response to anonymous inbound requests.