If there's one thing that's likely to ruin your day it's finding your Outlook personal storage folders file (AKA the .PST file) is corrupt.
Sure, Microsoft provides Scanpst.exe but if your PST file is over 2 GB then the tool will happily truncate the file which, to add insult to injury, may remove not just the oldest messages. Scanpst.exe is also prone to simply bombing for any number of reasons including weird installation issues, the day of the week, and the direction of the wind. In short, Scanpst.exe is unreliable and lame and is yet another tool that Microsoft just threw into the market and never bothered to finish.
Outlook Repair will find your PST files (although, oddly, it will also find files that just start with ".pst such as Limesurvey's .pstpl files) or you candirect it to whichever individual PST files you want to be repaired then fix them individually or as a batch.
Outlook Repair can also split PST files into files under 2GB to work around Outlook's perennial file size problem and even recover unattached attachments to messages. In short, it can sort out all of the problems that few other tools, particularly Scanpst.exe, can address. It's also fast fixing even enormous PST files in record time.
Priced at $262.45 (the odd price is probably due to currency exchange rates) it's pricey but as an enterprise tool to solve those annoying and pernicious Outlook problems it's cheap, cheap, cheap.