Active Directory - Default authentication

Question

Hi, I have the following problem. my application uses Active Directory, which is used for authentication. But, there is one independent ASP page in the same directory. To accesses that page, needs authentication. I want this page to be accessed either with a default login, password or without asking for authentication. my application sends an email with a link to this page. upon clicking on this link, should open the page without asking for login, password or should use a default login. how can do that? any ideas, suggestions will be of great help. Thanks in advance... Venkat.