Suddenly several Outlook mail accounts not sending nor receiving

Suddenly several accounts in Outlook will not send or receive. I receive an internal error message and am asked to re enter my password. I have one primary and 2 secondary accounts. At first just the secondary accounts would not send/receive. I tried re entering passwords and also deleted accounts and re entered them. After this deleting and re entering, ONE secondary account started working but then my primary and still the other secondary were not working. I deleted primary and re entered and still nothing happening.Everything was working fine earlier today.