如何在IIS中设置静态文件的可达性？

I have some static images in a folder on my IIS 6-based website that I want to be downloaded as little as possible (to preserve bandwidth). I've set the Content Expiration to expire after 30 days. Is there anything else I can do in IIS to try to maximize the caching by browsers, proxy, and gateway caches?I have some static images in a folder on my IIS