How to manage company departmental email IDs?

I would like to learn/understand how do big companies manager email addresses assigned to each department! I work in a company as IT Manager and I’m trying to figure our how should I manage departmental email IDs and since my company is located in multiple cities, the departments repeat as an example, I would have 1 finance team for each location/project, so shall I get them each a finance department email id, this way I will end up with 100s of department IDs and will have no idea how to keep track of who is responsible for which email ID! Can you suggest me a way to take care of this issues realistically!

My company uses Google Workspace for email services.