My Leopard machine is choking on Mail.app's index, bursting CPU utilization past 90% for sustained periods.
I noticed my Arq backup program keeps re-uploading a single 1.3GB file, and I have come to suspect that's the message index.
Ideally, I could "archive" items to keep the index from growing so big. Is that possible? Is that advisable? How can I reduce my massive Mail.app email index without actually deleting the data?