CDONTS Error

ASP content attempts to send mail on one of my sites hosted on IIS4 and NT Server 4 SP6a. The Web server is using Exchange for mail forwarding.
Resultant error message is:
Microsoft VBScript runtime error ‘800a0046’
Permission denied
/OG/tracker/flight_editper.asp, line 158

Line 158 is objMail.Send.

I have checked the permissions and all is good. Other people who use MS Frontpage 2000 for setting up email forwarding do not have this problem on the server. Any advice?