I am using the wrapper classes for .NET. I have downloaded the projects and I am able to get the contact list via Utility.
SearchContactByEmail on the searchContact.aspx with my username, password & apikey and a particular email. However when I plug in the dlls and access them from within my website I get the above error message. I am using the method within the Utility class and the same username, password, apikey & querying about the same email address. Any idea why I am receiving a 401 error?
Have you set your credentials correctly in the web-config file? That is typically the cause for that 401 error.