I work in an office with a hybrid Exchange/External POP3 setup and one staff member is responsible for maintaining the office's group calendar. Staff members frequently email her iCalendar entries that will automatically save to the group calendar when she opens them. However, if somebody tries to update an existing appointment and sends it to her, when they are opened they create new entries in the group calendar rather than updating the existing ones. Is there a way to have them update existing entries?

Thx