Using Outlook Express and receiving’ reported error (0x800CCC90) : ‘Your incoming (POP3) e-mail server has reported an internal error. If you continue to receive this message, contact your server administrator or Internet service provider (ISP). The server responded: -ERR Service not available (server error)’
When you telnet into your server using pop3 port 110 – you get an error “-ERR Service not available”. and you have checked to make sure that pop3 service is started and running.
On your Exchange Server – Exchange System Manager – Expand – Servers – Protocols – POP3 – Right click on Default POP3 Virtual Server and start the service.