Creating Teams for Community Language School

Good afternoon William

My question is "If there is a possibility to add members (Teachers and students) to TEAMS if they only have private email addresses? Please note that most of the teachers in these community schools are NOT part of any educational institution rather than the community language school they are teaching at hence we do not share the main domain, so I need to add them depending on their personal emails. Additionally, students in these community schools came from private and from public schools. How can I create classes (or levels) with wide range of different emails?