System.Web.Mail - Access is denied adding Attachments

[Guest]

Hi. I'm using System.Web.Mail to compose and send a message. I'm receiving
an "Access is denied" error message when non-Domain Administrators attach
files to the MailMessage.

My allows users to select files within a website folder, attach those files
to an e-mail, and send the e-mail. Domain Administrators can successfully do
this. But non-Domain Administrators receive "Access is denied" when
attempting to attach files. The message does not specify where access is
being denied to, and I really don't know how to fix this.

The website folder from which users select files for attachment has security
as follows:
- Everyone: Modify, Read & Execute, List FOlder Contents, Read, Write
- IIS_WPG: Modify, Read & Execute, List FOlder Contents, Read, Write

Can anyone tell me what the problem is? How can I allow non-Domain Admins
to attach files to an e-mail?

Thanks!