Basic mail is screwed up too
Thankfully I've gotten a Gmail address and as soon as I'm comfortable with it, goodbye Yahoo. For now...you force me to use Basic mail. Which of course has as many screwups as the "new and improved" mail. For one, when it says I have one new email and I open that mail, it STILL says I have one new mail and doesn't go away until I go back to the inbox. Two...when I delete a message I don't want to be taken to the deleted folder. Who would? As I said to begin with, I'm grateful Yahoo isn't the only email service on the planet. Plenty more to chose from and you've made it an easy decision to switch.
I'm not about to trash Yahoo! email at all. I have had it since its birth. BUT - and I receive very few emails - there is a sudden change - as you say, you open the new email, but it STILL says you have one new email and it does not go away until you go back to the inbox. There is no reason why this should drive me nuts, but it does, and I would like it to stop. (I would also appreciate it if "they" would stop assuming that everyone owns a mobile device. I do not).