Lots of places are fine with emailed CVs but there is the case that they can simply click delete when you see the title “Employment” or whatever you put.
If you snail mail it, someone WILL read it. Maybe not the person you hoped, but at least it will be read.
Also some people prefer to hold a piece of paper, and the glossier it is the better.
So, I reckon snail mail is probably better.
However,I’ve never done that, I’ve always emailed :) I’ve always gone with the approach of emailing and if they want more, they’ll ask me to post or email and I’ll oblige either way :)