For years any Intuit/Quickbooks invoice emails to my @att.net address (via yahoo mail website) just DISAPPEARED. I never knew they were sent and the sender was never informed of delivery failure. I don't know who is the problem - ATT or Yahoo but neither would acknowledge the issue. Please check on your end.
With this link I could set up (reactivate) an account with you (despite using Credit Karma and Quicken), hopefully such invoices will come to my email successfully.