I have no idea what they were doing to get the email addresses, I just know that I got an email that had all (three) of the email addresses I'd ever used in git

I have no idea what they were doing to get the email addresses, I just know that I got an email that had all (three) of the email addresses I'd ever used in github commits in the 'To' line. As far as recruiter emails go, it was not very good. Just a generic "we are hiring developers".