So, in case you didn’t already know (I did not,) your email address is publicly available form Github.
It can get scraped by anyone, or anything - quite easily.
Until now this hasn’t been an issue, but I just recently started receiving spam from people scraping Github.
Here are some resources to help keep your email address private on Github:
https://help.github.com/articles/keeping-your-email-address-private/
https://help.github.com/articles/changing-author-info/ (This will help you go back and remove your email address from public view)
Remember to report unsolicited emails as spam on Google to flag the sender with whatever service they use.