c# - ASP.NET MVC Windows Authentiaction and DirectoryServices - Get Mail Address of the current user throws an InvalidCastException

I am using ASP.NET MVC 4 and Windows Authentication.
When I am using VisualStudio everything works fine, but when I deploy my site an exception is thrown.

var emailAddress = UserPrincipal.Current.EmailAddress;

throws:

Unable to cast object of type
'System.DirectoryServices.AccountManagement.GroupPrincipal' to type
'System.DirectoryServices.AccountManagement.UserPrincipal'.

The rest works fine. Users can authenticate and I can get the users name etc.

EDIT:

I enabled Impersonation on IIS.
Now I get the following exception:

[DirectoryServicesCOMException (0x80072020): An operations error
occurred. ] System.DirectoryServices.DirectoryEntry.Bind(Boolean
throwIfFail) +781 System.DirectoryServices.DirectoryEntry.Bind()
+44 System.DirectoryServices.DirectoryEntry.get_AdsObject() +42 System.DirectoryServices.PropertyValueCollection.PopulateList() +29
System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry
entry, String propertyName) +119
System.DirectoryServices.PropertyCollection.get_Item(String
propertyName) +163
System.DirectoryServices.AccountManagement.PrincipalContext.DoLDAPDirectoryInitNoContainer()
+535649 System.DirectoryServices.AccountManagement.PrincipalContext.DoDomainInit()
+51 System.DirectoryServices.AccountManagement.PrincipalContext.Initialize()
+141 System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx()
+42 System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext

context, Type principalType, Nullable`1 identityType, String
identityValue, DateTime refDate) +27
System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithType(PrincipalContext
context, Type principalType, IdentityType identityType, String
identityValue) +146
System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(PrincipalContext
context, IdentityType identityType, String identityValue) +44
System.DirectoryServices.AccountManagement.UserPrincipal.get_Current()
+390 Jericho.MVC.HtmlHelperExtensions.GetUser(HtmlHelper htmlHelper) in
C:\Development\Jericho\Jericho.MVC\HtmlHelperExtensions.cs:48

What can I do?

Answer

Set the IIS Application Pool Identity to NetworkService and use:

var identityName = HttpContext.Current.User.Identity.Name;
using (HostingEnvironment.Impersonate())
{
    using (var context = new PrincipalContext(ContextType.Domain, "yourDomain", null, ContextOptions.Negotiate | ContextOptions.SecureSocketLayer))
    using (var userPrincipal = UserPrincipal.FindByIdentity(context, IdentityType.SamAccountName, identityName))
    {
        emailAddress = userPrincipal.EmailAddress;

        lastname = userPrincipal.Surname;
        firstname = userPrincipal.GivenName;
    }
}