Same in Germany. Letters sent by fax legally count as "written" correspondence while email does not. I am 23 and I can remember times, when I (theoretically) had to cryptographically sign a PDF to send even an invoice by email.
In private homes fax machines are the exception but in businesses of every size, they are still pretty common.
Our chancellor famously said in 2013 "The internet is new land for all of us." [0]
We keep inventing technologies like De-Mail [1] or the chip on our ID card [2] to authenticates you online - if you could only find a services that implements the protocol and you would have the required card reader. I guess most of this audience would not even understand the need for an offline ID card …
Focus on security is a good thing - especially when I read stories about how criminals claim refunds from other people's IRS accounts in the US, but email is in no way easier hackable for the average person than postal letters are. And postal addresses will not give you unique identification either.
I also love when I ask the German version of the IRS a quick question by email and get the answer back by postal letter with my email printed and attached to it. Gives me the warm feeling, that you can count on some things to stay the same. :D
[0]: http://knowyourmeme.com/memes/events/neuland
[1]: http://en.wikipedia.org/wiki/De-Mail
[2]: http://www.personalausweisportal.de/EN/Citizens/Electronic-I...