Emailing invoice from Quicken indicates email sent but they are never received

Just started using Quicken Business-Rental. Yes, I am still using an aol email address for my business. I have created an invoice, then selected the option to email the invoice. The email appears to be sent from Quicken however the invoice is never received.

I have seen a few other posts about this but nothing recent and I can't imagine these problems are not resolved by now. Anyway I did try to email the invoice to my personal gmail account after reading other Discussions but it is still indicated sent in Quicken and nothing is received.

What is the latest update on this problem?