I have 4 pop email accounts in Outlook 2010. All are configured properly, in that up until recently, they all sent and received email just fine. I have not made any changes that I am aware of to Outlook or the accounts. I have also verified login information through the Web email client of the relevant providers - I can log in on the Web email apps and check mail on all 4. In addition, I have contacted the providers to validate that the server settings (pop3 and smtp, ports, ssl, etc.) are correct and have not changed.
Now for Outlook itself. I can send/receive from 2 of the accounts and not the other two. In Send/Receive groups, I see only 2 of the accounts, even though all 4 appear in the Account Settings dialog. In the Account Settings dialog, if I select an account to move it up or down or make it a default, I receive the cryptic error "The specified Account was not found. It might have been deleted." Clicking the Send/Receive button will not send/receive on any of the accounts, including the 2 that seem to be valid.
Two of the four accounts are from the same provider (at&t), and the other two are from their own same provider (network solutions). One of the at&t accounts works, and one of the NS accounts works. The settings, other than user/pw, are the same on like accounts (port, ssl, smtp, etc.)
I have tried removing the offending accounts and adding them back: no effect. I have run the Outlook repair utility: no effect. I have uninstalled and reinstalled Office: no effect. I have searched the Web at length: no useful information.
I really need for these accounts to work. Has anyone run into this situation before and know how to resolve it?