No-reply email account without taking up a user license?

I just upgraded our zoho mail account to the paid tier and purchases 7 licenses. When setting up our new users I can't add the 7th one because I have a no-reply email account created to be able to send automated emails from our server.

How do I go about having an account like that without taking up a user slot? All it needs is outgoing mail, no receiving or anything else.