need help cannot send email

I have Windows 98 on this gateway. the dsl is connected
through the wireless usb adapter. Dsl works great, and I
can check my web based email, but cannot use Outlook. Get
an error message that it cannot authenticate server. pop
and smtp settings are correct. the error code is
0x800ccc0f. I disabled the firewall as a troubleshooting
technique, but got nowhere. my isp and computer
manufacturer hasn't a clue what to do! the oper. system
is 98, the Outlook is 2000. Does this make a difference?
Any thoughts are appreciated.
I'm still stefie from the block...