I was just able to get it working with Yahoo, but I had to enable in Yahoo Security settings to allow less secure apps to use the mail account. So success at last! Thank you!
I have the same issues with Gmail and have just now created Hotmail and Yahoo accounts. I've tested both ports 465 and 587 as well in all combinations with SSL and TLS however I keep getting "Test Failed." in my Dahua NVR. No success.