Try this...
Open Outlook, go to the tool/account tabs.
Click on you verizon account to open the properties... Choose the servers tab. Make sure the little box next to my server requires authentication IS checked. If you his the properties box next to that, it should read:
[you're email adress here]l#incoming.verizon.net
[you password here]
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For some reason, when I installed avast, it changed my account around and that box was NOT checked. It was an easy enough fix.
If it's not that... I am at a loss.