Delphi – 从活动目录获取用户EmailAddress

我试图通过使用Active Directory中的sAMAccountName来获取用户的电子邮件地址,但我收到此错误消息：

The directory property cannot be found in the cache.

我可以获得全名,部门和自由裁量权,但为什么我收到电子邮件的错误？

uses
  ActiveDs_TLB, adshlp;

procedure TMainForm.btnFillInfoClick(Sender: TObject);
var
  Usr: IAdsUser;
  lStr: HRESULT;
  xStrg: string;
  ChkPRN: string;
  RemoveDot: string;
begin
  //connect to AD and try exrtact the info /
  lStr := ADsGetObject('WinNT://10.120.200.16/'+edtPRN.Text, IADsUser, usr); // edtPRN.Text >> sAMAccountName
  if Succeeded(lStr) then
  begin
    Usr.GetInfo;
    EmpFullName := Usr.FullName;
    RemoveDot := StringReplace(EmpFullName, '.', '',[rfReplaceAll, rfIgnoreCase]);
    xStrg := Usr.FullName;
    edtLastName.Text := GetLastWord(xStrg);
    xStrg := StringReplace(RemoveDot, edtLastName.Text, '',[rfReplaceAll, rfIgnoreCase]);
    EdtMidName.Text := GetLastWord(xStrg);
    xStrg := StringReplace(RemoveDot, EdtMidName.Text, '',[rfReplaceAll, rfIgnoreCase]);
    xStrg := StringReplace(xStrg, edtLastName.Text, '',[rfReplaceAll, rfIgnoreCase]);
    edtFirstName.Text := GetLastWord(xStrg);
    edtEmail.Text := Usr.EmailAddress;  // <<<<< this is the error 
  end;
end;

使用WinNT：//提供程序无法使用电子邮件地址属性,您需要使用LDAP：//提供程序.该属性的名称是’mail’而不是’emailaddress’.这是ASDI和Delphi的链接. ASDI examples.