On my system I don\'t have the user.email git configuration value set at the global level, on purpose. Instead, I configure it individually in each sandbox. This is
It would be very hokey and possibly break in edge cases, but you could write a system-wide post-commit hook that looks at the author of the new commit and undoes it (via git reset) if it appears to be bogus.
Other than that, no, Git is happy to use whatever ridiculous email address it cobbles together as a default.