How can I find out if group members on our group signed up with their corporate email?

My company has a large group on, we’ve been making an effort to ensure that people have been signing up with their corporate email account and not using personal Gitlab accounts (for security reasons).

I need to be able to audit the group members to make sure that this is the case for everyone, however:

  • Email is not listed on the members page
  • The Gitlab API only allows access to user emails by admins, and obviously I’m not an admin of

How can I audit our group members, short of removing every one of them and re-adding?