asp mail on windows 2000

the problem that i am having is that anytime i submit a email from the website i have, it prompts for username and password. however when i send the email from the webserver itself it sends. it is obviouse that it wants to authenticate the browser for sending mail but this was not the case with cdonts.dll i thought at first it was jsut having a problem posting to the server but i found out that was not the case. if anyone out there knows anything about asp mail with win 2k or has heard of this please let me know.
thanx
chris