"Nothing to hide, nothing to fear"
Has become
"Autonomy is pointless, resistance is futile"
In about a month.
You need to remember the fact that already Snowden's revelations have proven that the NSA and other government agencies all have specific budgets for astro turfing activities (manipulating the public opinion by massively participating in online discussions).
And a couple of days ago, there was a nice post on Reddit's front page summing up the situation on Reddit. Reddit is basically completely compromised by whoever has lots of money (government, big industries, etc). Any company can buy astro turfing services nowadays.
So no, you can't trust public online discussion anymore. Not on Reddit and not here. Unless for topics you are absolutely certain that no economic interest is part of the equation.
I mean, the governments of those places will probably snoop your emails, but if their contents have nothing to do with them, they won't care. And they have no treaties with the US to force their hand to turn anything over.
Think of your server as Edward Snowden. What country should it hide in, so the US can't legally get to it?
Can't you say the exact same thing about the US government?
Sure, but that doesn't mean they won't happily exchange that info as part of a deal with the US, assuming your data is valuable enough.
Uhm, how? Gmail supports Transport Layer Security (TLS), and >80% of their emails to and from other providers do as well (https://www.google.com/transparencyreport/saferemail/). Reject non-TSL emails, give the server a public key and tell it to throw away the email plaintext, and the only remaining threat vectors seem like "get rubber hosed into disclosing your private key" and "server gets compromised, causing future emails (but not past ones) to get exfiltrated".