My invoices are not delivered to the accountancy software, although I have configured the right e-mail address. How come?

Some accounting software vendors require you to explicitly confirm the email addresses from which invoices will be sent to the accounting software. We also call this 'whitelisting'.

The e-mail address that you must provide in that case is noreply@okioki.be.

Exact Online e.g. requires this additional confirmation. More about this in their article on troubleshooting the digital postbox of Exact.