Once downloaded, email is generally stored in a PST (Personal Storage Table) file. It’s simply a file with .pst at the end that holds email data (messages, contacts, calendar, etc).

Not everyone who uses Outlook stores data in a PST file but generally: if your email is available whilst not connected to a network – it’s stored in a PST somewhere on your hard drive.

Just as snail mail is delivered to a mailbox; electronic mail is delivered to file – a PST file. As you receive more and more email the size of the file increases – messages, attachments, contacts and other data add to the size of the file – maintenance becomes necessary, especially if you don’t delete regularly.

If you don’t perform maintenance, Outlook becomes slower; the file becomes larger, unmanageable and eventually corrupt.

Imagine what would happen if you stored your snail mail, catalogues and junk mail in your mailbox – removing it to read, then returning it to the mailbox for storage.

Of course, nobody does this – it’s ridiculous to continue stuffing a massive amount of items into a confined space and I’m sure your mail deliverer wouldn’t put up with it.

But for some reason we think email is different – that an unlimited amount of email messages with pictures and other attachments can be kept; that the deleted items never need permanently deleting; that the sent items can be kept forever – that we can let our PST get bigger and bigger and bigger.

Well, depending on what version of Outlook or Outlook Express you use; you need to keep the size of your PST to a minimum.

If you use version 2002 or a previous version you must keep your file size under 2GB. Improvements were made after this, so if you use version 2003 or 2007: you shouldn’t have problems until your file size reaches 20GB.