I just don't understand how companies can think this kind of privacy invading marketing can be effective. In which situation do they believe they are adding affinity for their product by scraping your email?
Ah yes, the "one bad nerd-apple" hypothesis.
https://docs.github.com/en/site-policy/github-terms/github-t...
> You may not use the API to download data or Content from GitHub for spamming purposes
Report each instance of spam to GitHub, and hopefully they'll terminate the account.