Using PST files (Personal Storage Table files) in Microsoft Outlook has been a common practice for storing email messages locally. However, there are several reasons why their usage is often discouraged by Microsoft and ITS.

Pros of PST File Usage:

1. Local Storage: PST files allow you to archive old emails that you don’t need regularly but want to keep for future reference. This helps in decluttering your mailbox. It is also one method of keeping your email available offline.
2. Data Transfer: Facilitates the transfer of email data between different computers or people, such as when an employee leaves the University and wants to give the department important emails they were storing.

Cons of PST File Usage:

1. Data Risk: PST files are prone to corruption, which can lead to data loss. The larger the file, the higher the risk.
2. Security Vulnerabilities: Stored locally, PST files can be a security risk if not properly secured, making sensitive information susceptible to unauthorized access.
3. Compliance Issues: Managing and securing PST files can be challenging, potentially leading to compliance issues with data protection regulations.
4. Backup and Recovery Challenges: PST files stored locally are not automatically included in most computer backups, making it difficult to recover lost or corrupted data.
5. Data Silos: They create data silos, with information stored separately from the centralized email system, complicating data management and discovery.
6. Performance Issues: Large PST files can significantly slow down Outlook performance, affecting productivity.
7. Microsoft's Stance: Microsoft discourages the use of PST files for these reasons, especially with the availability of cloud-based solutions like Online Archiving for Outlook mail users, which offer more secure and reliable email storage and archiving options.

ITS Recommends:
When storing large amounts of email necessary for ready reference, you can request the ITS Help Desk enable Online Archiving for your mailbox. This will provide a separate set of archive folders with their own 100 GB quota by default.

• These folders are available through the Outlook desktop apps on PC and MacOS or via Outlook on the web.
• By default, emails two years old or older will move to the online archive automatically, but individuals can apply policies to their account or at the folder level increasing or decreasing the age of the email to be archived.
• If even more storage is needed the ITS Help Desk can make the Online Archive auto-expanding so that it provisions more space as it fills up.