How to add attachments to appointment?

appointment.Attachments.AddFileAttachment(file.Name, stream);
//appointment.Attachments[0].IsInline = true;   disabled in Outlook 2007
appointment.Save(WellKnownFolderName.Calendar, SendInvitationsMode.SendToAllAndSaveCopy);

The recipient can't see the attachment

The sender can see attachment from the calendar.

In outbox, the mail hasn't attachment.

What's wrong?