My email is public on my GitHub profile (it's the same as my git author email, which is also public) for the last few years, and I don't have a huge problem with spam. I get a couple emails occasionally (a few every month), and they're easy to say "no thanks" to.

What made the most positive difference was deleting my LinkedIn account, I was getting way more spam there (via its own messaging system, not via email) that was very unpleasant.