Iirc when doing it support in college an incoming email to the support address would create a ticket with threading, Where a reply would be a reply to the custo

Iirc when doing it support in college an incoming email to the support address would create a ticket with threading, Where a reply would be a reply to the customer as an email or you can also have internal conversations with your team members and tag and lock things as well. Osticket iirc