card party
A virtual party for which guests individually mail greeting cards to the guest of honor. Organizers of the party identify a list of friends, relatives, colleagues, etc. and contact them, inviting them all to send cards to the same person to observe/commemorate a special occasion in the life of the guest of honor.
Two weeks before she turned 70, Phyllis' kids organized a card party. She was surprised by the volume of birthday cards she received from so many friends.