How use non-visual components in ActiveX Library (COM Server)

I am writing an ActiveX Library using Delphi,
but there is a problem need your hellp.
How to create or use Delphi non-visual compoents in ActiveX Library (DLL),
bellowing is my source code:

------- Part of Source code -----
uses
  ComObj, HelloDll_TLB, classes, tcpip;
  TTAXSMTP = class(TAutoObject, ITAXSMTP)
  Private
    SMTPServer: T_SMTP;        <----- here is a componet
    Mail: T_Mail;                       <----- here is a component
  protected
    procedure Execute; safecall;
    procedure Init; safecall;
    procedure Free; safecall;
  end;
implementation
uses ComServ, SysUtils;
procedure TTAXSMTP.Init;
begin
   SMTPServer.Create (self);      <---- I can't create it, because TAXSmtp
                                                          is not
compaitiable with TComponent
   Mail.Create(self);                    <---- I can't create it, because
TAXSmtp
                                                          is not
compaitiable with TComponent
   Mail.SMTP := SmtpServer;
   Mail.Recipients.Clear;
   Mail.Body.Clear;
end;

----- End of Source Code ----

If you know how to slove that, please tell me, thank you!

Regards,
    Jolios Lin