That still sends out an email. The initial "Our customer care team personnel has created a ticket #123456 on your behalf, with the following message;" email. It can be used to suppress some of the emails though. For example, if I open a ticket with
email: smoogles@fakemail.net
It will send the "Our customer care team personnel has created a ticket #123456 on your behalf, with the following message;" email to smoogles.
Then if a staff updates the ticket, it will send out the "Our customer support team personnel has replied to your support request #123456" email to smoogles.
It won't send out department notices though.