No, Socket Error: 10061

Dear all

I have a question on Redhat sendmail. I have install and configured IMAP and POP (with telnet successful). When i use Outlook Express connect the Server, an error occurred on ” The connection to the server has failed. Account: ‘[domain name], Server: ‘[domain name]’, Protocol: POP3, Port: 110, Secure(SSL): No, Socket Error: 10061, Error Number: 0x800CCC0E

Is there anyone can give me advise how i can send/receive mail by Outlook Express?

Best regards

Jimmy