Confirmation that client received invoice?

Confirmation that client received invoice?

I would like to know if Zoho invoice has a notification area that tells if and when a customer opens an invoice sent via email.
I think this would be a great option since its common for spam folders to hide incoming emails. 
It would also save me a bunch of time to know if a customer received an invoice instead of having to call them to ask.
If the software doesn't have this feature, does anyone if there would be a way to add email delivery confirmation.

Thanks 

David