Hola Abraham, al parecer la propiedad Add no existe, en el codigo de abajo reemplacé tus "adds" por "Items"
procedure TForm1.Button1Click(Sender: TObject);
var Mail: Variant; begin Mail:= CreateOleObject('CDO.Message');
Mail.From:= 'ingeniro_abraham@hotmail.com';
Mail.Subject:= 'Saludo';
Mail.TextBody:= 'Cuerpo del Email';
Mail.To:= 'ingeniro_abraham@hotmail.com';
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/sendusername'):='abraham';
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/sendpassword'):='clave';
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/sendusing') := 2;
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/smtpserver') := 'www.hotmail.com';
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/smtpserverport') := 25;
Mail.Configuration.Fields.Item('http://schemas.microsoft.com/cdo/configuration/smtpconnectiontimeout') := 60;
Mail.Send;
Mail:= Unassigned;
end;
saludos.
