Also, must the "reply to" email address actually exist?

For example, I have a sender email "sender@example.com", and the "reply to" email address is "info@example.com". In this example, do I have to pay money to maintain both email addresses?

At the moment, I control the domain and pay Zoho to maintain both email addresses. Do you provide them for free? Or do you have any suggestion on how to manage cost for startup founders?

Please let me know what's the best practice and elaborate a bit more detail if you can.

Thank you.