First of all, I am running Outlook in cached mode.
I place the personal folders and archives pst files on the local machine (c:\Outlook *.pst). I then run a batch file to copy the files up to the server once per week. The only thing in doing it this way is that Outlook has to be closed before copying the pst files up to the server. If you want, I can email you the cmd file that I used as the template for this.
I do it this way so that if the hard drive crashes, I don’t loose much personal stuff. By the way, M$ doesn’t recomend that you run Outlook with the pst files located on a server. Haven’t looked into the reason for this, but is what our Network Admin has been telling me.
I know here that anything that resides on the exchange server counts towards the size limit that each user has. It used to be that each user had a 20 MB limit on the size of their mailbox. That has been bumped up a couple of times with the latest one 3 weeks ago giving this: