It appears that, if you don’t configure your account email settings correctly in GitHub, it’s possible that your email address is exposed in your commit history:

GitHub does provide an option to mask your commit email address, replacing it with a redirect e-mail which looks like: <a generated number>+<your username>@users.noreply.github.com. It’s under Personal Settings → [Emails](https://github.com/settings/emails).

There is also a way to go through and edit your commit histories. The following has the instructions with a bash script you can run:

This seems tough to do if you have many repositories, but I suppose that someone who has that many would be likely to know how to automate on his or her own.