Can't send mail in OS X 10.0.3


When using the Mail application in OS X 10.0.3 I am unable to send email through any smtp server (i.e.,, Keep getting an error saying that the server refused to open port25.

When using Outlook Express in OS 9.1 I am able to send email through both of the smtp servers listed above. Any ideas would be much appreciated!
thanks! I'll check it out, though I am a bit cautious since the fix if for os x 10.0.2 and earlier.
Actually, I'm using 10.0.4 now and still have that problem. I've noticed that if I switch ISP's (i.e. if I switch to Earthlink) I am able to send. With my other ISP (Metconnect), which is who I want to stay with, I am unable to send. :(

Any ideas other than switching ISPs?