I have windows 98SE and I am using Outlook express6.0 I have been having problems sending messages lately. No problems receiving e-mail. Sometimes it will send and sometimes it won't. I would receive an error: "An unknown error has occurred. Protocol: SMTP, Port: 0, Secure(SSL): No, Error Number: 0x800C0131". I would close OL at the point. An "unsent message" would appear asking whether I want to send message or not. If I click yes it would send it most of the time. If not I may have to re-open OL or rebootat certain times. It would sent the messages as soon as I re-open OL. It does not matter whether I have attachment or not. Any suggestion?