Help yahoo email sync issue

[maltz]

I had to clear out some data over the weekend on my phone and somehow deleted my mail accounts by mistake. I now have reset all my email accounts and am back up and running. My only issue now is that the stock mail app for my yahoo email used to be in total sync with the yahoo web mail. If I read an email on the web page, my phone would show it was read as well. Now, they are not at all in sync and I am having to open all my emails on my phone and deleting them as well, I did not have to do that as of last week. Is there a setting that I am missing?

Would anything change if I enter my yahoo plus info? I do pay for that service?

Thanks