Godaddy email system is not reliable (but depends on the hosting plan). Sometimes emails are delivered sometimes not. Is not about the scheduler. Ask Godaddy support which SMTP you can use and install an SMTP plugin to connect the blog to that SMTP (if they give you one).
If they give sn SMTP, usually that solves the problem. Connecting the bog to an external SMTP typically does not work with Godaddy since the blocks that kind of connection.
A good alternative is to use a pro delivery service (SendGrid, mailjet, …) and connect to them with a plugin that uses their API, Godaddy cannot block those kinds fo connections. That is what we do with our delivery addon, for example, not coded for godaddy but to have better performance and bounce management.
Some free SMTP plugins have specific integration with delivery services using the API and they could be a solution when dealing with Godaddy.
Anyway start reporting the problem to Godaddy.