OutlookTools 2.3 is a useful tweaking tool for Microsoft Outlook 2000, 2002/XP, 2003, 2007 and 2010.
At its simplest, you can use the program as a quick way to discover useful information. Do you know where Outlook keeps roaming and local data, for instance? What about the temporary folder where it opens attachments? There are probably leftover files there from previous Outlook sessions, but OutlookTools can delete them all in a click.
OutlookTools can apply many useful Outlook tweaks. Would you like the program to minimise to the system tray, for instance? One click will make it happen. Tired of the desktop alert for new mail? Shorten its duration here, or make the alert more transparent. Need to receive forbidden attachment types? Click the Blocked Attachments tab and select the files you'd like to allow (though be careful - this will compromise your security).
And if you're technically inclined, there's a lengthy list of 49 command line switches that will change how Outlook behaves, the next time it's started. If the program won't launch, for instance, use the /safe switch and it'll load without addons. The /cleanprofile switch can fix some Outlook Registry issues, /firstrun opens the program as though it's been launched for the first time, and there are plenty of other troubleshooting and management options to explore.