I retain basically 100% of my emails. I am willing to trade off storage space on a hard drive in exchange for the constant timesaver of not having to hunt and peck what to delete and what to retain. if I ever need to refer back to a message, I can do so quickly with keyword searches, filters, etc. It never fails me.
To prevent overload on Exchange server, I keep my Outlook .ost file clean as a whistle. As soon as I read a message, I immediately move it into an ever-growing .pst file that I have stored on a separate hard drive (where I can use as much space as I want).
Questions out of all of this...
1. At some point the file size of my external .pst will slow down the performance of Outlook, yes?
2. Is there some kind of official or rule of thumb maximum size for a .pst? I have heard it becomes "risky" at some point.
3. If I end up needing to create a fresh .pst every 6 months or every 1GB or whatever...how would I be able to search through all the individual .pst contents at the same time?