I'm not a Mac person and I'm trying to deploy the installer for iSync for my Macintosh users. My instance is being maintained by an ASP, and they provided me with a zip archive with the iSync installers. I am trying to place this onto a web server and point my users to it so they can begin the install over the web.

The zip archive creates a folder called "Zimbra-iSync-0912.pkg". The PDF walkthrough I have tells Mac users to click on this item in order to launch the installation process. However if I'm delivering this to them over http, what steps would I need to take to ensure that their local machines recognized it as an installer file as opposed to a folder? My apologies for such a silly, fundamental question; I just don't have much experience with Macintosh support so have do do a lot of guesswork.