All of our users are now on Office 365 where there mailbox limits are 50Gb. Office 365 users should not need to create .pst files and are strongly discouraged from doing so.
- Click File, Open, and then Import to start the Import and Export Wizard.
- Select Export to a file and click Next
- Select Outlook Data File (.pst) and click Next
- Choose which folder you'd like to export to a .pst, and whether you'd like subfolders to be exported with it. Then click Next.
- Choose where you want the .pst file saved to, and click Finish.
To connect this .pst file back to Outlook at a later date, please see the article called Open .pst files in Outlook.