I never had any issues with any of the email systems on my phone before the kit kat upgrade. Ever since the upgrade to kit kat, I am having issue with only one of the email systems that was working perfectly fine before the upgrade. My gmail and Yahoo continue to work fine. Coming to this other email, even though it is synchronizing my emails, I also see a duplicate icon for the same email in the notification bar. When I open it, it says log in failure and asks me to either update the settings or cancel. I have to keep cancelling the window and open the other icon (for the same email) to check my mail. It happens several times in a day. I tried to remove that email system entirely, then go to settings, add account, choose "email" and entered the settings again but it continues to show the error window. This is for my Yahoo small business mail. Could someone please advice how I can fix the problem. I am a VZW customer on Moto X. Thanks.