Re: Your high horse is getting tired...
We had so many problems due to that 4Gb limit when I worked in a local authority. Our policy was very clear that e-mail wasn't a file storage tool and they should be keeping important stuff on their network drives so it could be backed up. The PSTs couldn't be as our infrastructure wouldn't support dragging such massive files back and forward on our piddly little broadband connections between sites even if we'd wanted to.
The "fix" wasn't to train and educate users in why we got them to do it (basically to avoid the problems in this article) but instead to simply create an additional PST when the old one filled up but keep both attached so users could double dip to their hearts content.
Needless to say the first time a director lost his PST due to a HDD failure we were forced to pay over 2 grand for an attempt to recover the files then suddenly this policy became rather important.
.. for about two weeks before everyone just continued as before.