I am getting the following Error: 0x800CCC19 in Windows Mail on Vista connecting to my FIOS email account. Was working fine, but just started getting this yesterday. Tried clearing out all email through the web mail access, but now it's doing it again today. This has been working for over a year, so don't get it.
From Microsoft's support website:
These error messages may occur if Microsoft Outlook or Microsoft Outlook Express cannot establish a connection with your e-mail server. These error messages are frequently caused by one of the following:
The support page for this error is located here and contains some troubleshooting steps you can try. My first step though, if it has been working and suddenly isn't, would be to check you antivirus/security software. They may have pushed an update through that enabled/altered an email scan, causing the timeout.