Why is my client not receiving invoices?

If you have sent an email, and it says "delivered" within the finance portal even though the client is still not receiving it, that can usually mean two things:

1. Their inbox is full and they have no space to receive emails - the solution is to empty and clean up the inbox.
2. They have blocked your emails - The Solution: The client has to unblock the IP - Remove blocked users from the Restricted entities page.