Yep, I imagined it would be a problem in the US. I am in the UK though, where you pretty much don't have to do anything as far as taxes go when you're a simple employee, and if you do have to deal with the taxman, you can do pretty much everything online and get email notifications.
However, wouldn't important letters (like urgent communication from the IRS or similar government agency) that could have consequences if unread be sent as registered letters (where at least in the UK and France the mailman personally hands it to you and asks for a signature)?