I just caught myself cleaning out my PMs. I do this on every forum; organize them into folders, delete them if they're superfluous, etc, and I was wondering who else does this? I know of people who have thousands of PMs, some years old, that are just sitting there because they can't bring themselves to delete them (I know this because they do it on my site!).
Do you let them accumulate? Do you delete them? Do you track them?