I want to put the Exchange 2016 server into maintenance mode before rebooting it. The first command is to Drain the mail queues on the server.
Set-ServerComponentState EX16-1 -Component HubTransport -State Draining -Requester Maintenance
Question: What does it mean by draining the mail queues. What would this command do on server? I want to understand it practically . Can some one explain please.