G'Day Folks,
Can DO synchronize Microsoft Office "outlook.pst" files, i.e. the content of the .pst file it's folders and email messages ?
If not, does anyone know of a good utility program that can do this job ?
Regards
pcbugfixer 
No, Opus doesn't have any special understanding of PST file contents; they are just data files to Opus.
I tried SynchPost (http://www.synchpst.com/) out for a while last year and seemed to work OK over my network between my main PC and my Laptop. I don't know if it works over the Internet or not as I didn't have that requirement. You can select individual mail folders etc.
I have used synchpst for some years. It has become steadily faster and more user friendly over the years.
It works between two different installations of Outlook. If the need is for something else – such as synchronising a desktop and a mobile phone – then you need something else. Most of the phones I have owned come with their own software for this.