What to do about Outlook's huge PST

.pst files are one of Outlook's repositories for email, contacts, calendar information and quite often much, much more. There's a physical limit on .pst size that's up around 2 gigabytes, but more practical considerations like speed often make us want to control the size well before reaching that stage.

Step one is pretty obvious: delete what you can. Remember, though, that when you delete an item in Outlook, it is simply moved to the Deleted Items folder, which doesn't actually free the space until you empty it. So right click on the Deleted Items folder and select the Empty "Deleted Items" Folder to permanently delete its contents. This will free up the space that the delete items took. But it will not, immediately, make the file smaller.

Step two: after you've permanently deleted what you can, it's time to compress. Microsoft has a knowledge base article about compressing your .pst. (see this KB http://support.microsoft.com/?kbid=289987 )

In short: File->Data File Management, select your Personal Folders, Settings, and then Compact Now.If the resulting file is still too big, then it might be time to create an additional .pst. Outlook supports having multiple .pst's open at the same time. Your existing "Personal Folders" will remain the destination for email, but you can easily move items into another .pst file.