This is by far the most frustrated I have ever been with Verizon. Email has always been the most reliable part of my service. But now all of a sudden out of the blue I have 2 laptops, one desktop and my I phone 4S not working with Verizon email via Outlook or I Phone email app.. I have tried all the on line fixes, called support and got no where. The problem is this, Both Outlook, Outlook Express and the I Phone are all telling me I need to enter my password and login, which is in all three devices correctly. I have changed everything I can in every possible combination and am now back to the settings when the problem began last Thursday. The strange thing is that Saturday morning it started working again and then later in the day failed again and went back to asking for my password. I am Verizon Yahoo email user and am able to log into Yahoo Verizon and the Verizon site no problem. The thing that toasts me is the excuse that Outlook is not a Verizon product so they can't help. So here I sit on the road tied to webmail and no Verizon email on my phone. Any help appreciated.
Not sure exactly what's causing your problem. The error message might shed some light.
One thing I do know is that the Verizon/Yahoo seems to sometimes randomly switch between requiring the @verizon.net portion in the username, and not allowing it.