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?

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;
    }
}