Users of Microsoft’s Outlook email and PIM client have come to expect that over time their .PST file will grow significantly, particularly anyone that does a large volume of emailing. The growth of the .PST file can be problematic for a number of reasons. Firstly, heavy users of Outlook anecdotally report that the larger your .PST file is, the slower Outlook becomes. The recommended action is to regularly archive messages out of your main .PST to an archival file on a regular basis. However there is a bigger issue: versions of Outlook prior to 2003 do not support .PST files larger than 2 Gigs. And worse, Outlook does not do a good job of monitoring this situation, so when the user exceeds 2 Gigs, .PST corruption results and invariably some messages are lost.

To combat this situation, users can use the built-in Compact command, which will cause Outlook to try to recover any empty spaces within the .PST file. It can be helpful, but Xemplify IT have come up with something better: PSTCompactor. PSTCompactor can reduce .PST files by as much as 38% by using a combination of techniques including compressing attachments and physically removing deleted items rather than leaving them in place marked as deleted.

At  $24.95 for the home version, PSTCompactor will not break the bank, and might well save you the space you need. They even helpfully provide a freely downloadable version that will scan your .PST files to determine what if any benefit you would get from using their product. It won’t actually compact the file, but will tell you the percentage of space you will regain by using their product.