Your issue is actually no. 2 m8, they may revert to IMAP to be honest. Issue occurs because the server has responded to an IMAP approach though your account on it is POP3.
If not receiving mail to the device (though RIM has polled your e-mail accounts without an issue) then this suggests either a RIM -> network issue or a GPRS issue. If device off/on works then suggests an issue with GPRS session/mobility management (GSM network).