Can I Send a Yahoo Greeting eCard to a Yahoo Group?

Hey Folks! I am the moderator of a couple of local Yahoo Groups ~ and I really want to send them an eCard for the holidays. There is over a hundred members ~ so adding all personal addresses is just too difficult. I have tried it once before ~ but only the first person to open it was able to view it. I am missing some detail to make it happen ~ if it is even possible. Anyone know if this can be done and how to do it? Thanks so much!