Fanmail.biz

If I plan to send out to several actors in the same show at the same address, would it be advisable to send them all individually or could I put them all in one envelope and just address it to the show in general? I have no way of knowing but I'm guessing somebody handles all the fanmail before it gets passed on to them? I've just seen a few successes recently where somebody wrote to one cast member and received a photo back signed by everybody so I thought it would be worth a shot. It sure would save on postage

Best to send each letter individually, I've found.