Worse than coming back undeliverable, my invoices and statements show that they have been sent in QBO, but they have not!  They never arrive at the destination.  I have tried emailing things to myself at my own address from QB but nothing.  It says it was sent but it never arrives. (Not in spam, not in anywhere.)

This only happens sometimes and to certain customers, but not others.  It is random and there is no way to know whether the invoice or statement was delivered or not short of calling or emailing the customer.  This is very unprofessional.

I logged a call to QBO, was told "they are working on it", they could not say when it would be fixed.

In  the meantime they told me to print my invoices and statements and send them manually from other software!   That was the whole point of buying QB  - so that it would do that for me!

So angry and frustrated.