I am relying on my web host mailer function. It must be working because Forgot Password? on the login page sends out an email. But when issuing invoices I (parent) do not receive an email invoice, receipt etc. What can I check?
I would start by checking the mail log to see if there are any clues there. Your host can help you to access this, as it is often protected in a shared hosting environment (to avoid you seeing someone else’s log entries).