Finding out who I BCC'd

As a responsible email user who respects the privacy of my friends, I always use BCC when sending out invitations, information etc to a large group of people. My email client on my Mac allows me (and only me) to see the list of people to whom I sent the email as it preserves the BCC information in the sent items folder. the iPad appears not to do this - I now have no idea who has an invitation from me. Has anyone else noticed this? does anyone else find this a problem?