When e-mail messages are in a .pst file, you can give a copy of that file to a co-worker.
When e-mail messages are contained in a .pst file, they're portable. That means that you can share those e-mail messages with other people simply by giving them copies of the .pst file. The other people would open it and use it on their computers in their own versions of Outlook.
An easy way to create a copy of e-mail messages is to use the Import and Export Wizard to copy them to a .pst file. (When you use this wizard, the .pst file is created for you automatically.) Another way is to close Outlook, find the .pst file in Windows Explorer, and create a copy of it there—just as you might make a copy of a Word document or any other file.