Since almost the beginning of on-premises Exchange organizations have been using PST files.  These provided our organizational users an option to save their email when Exchange disk options were expensive.  Notice I say disks “were” expensive.  This was in the early days of Exchange back in the 1990’s.  Today this simply is not the case, disk is affordable regardless of whether or not you choose to implement on-premises Exchange preferred architecture or not.

One of the other challenges of years ago that led us to the use of PST files was mailbox sizes were kept small, in fact a 50 MB mailbox was the accepted standard per user.  Storage costs were the main driver, but also this was during a time when organizations didn’t realize the liability that could come with not keeping email from a legal and compliance perspective.  Getting rid of any email was almost completely acceptable in the 1990’s and we were just learning the ramifications on not properly retaining data.


Finally, Enterprise archiving options were new and few.  We were just learning why we would use true archiving solutions, and didn’t have much to pick from in the way of options.  So why implement it when we could use Outlook PST files?

The Challenges

Over the years we have learned a few things about Outlook PST files that has Exchange administrators cringing almost as much as when we hear the words “public folders”.  Public folders I will hold on though, as that is a completely separate “can of worms” to discuss.

So why would an Exchange administrator cringe at PST files?

For one they were not designed to function well on a network share.  They were intended to live locally on a workstation where administrators couldn’t back them up.  Those administrators that chose to put them on a network share, so they could be backed up caused great challenges for this files and organizational users due to file corruption.

Another great challenge within Outlook archiving to PST is that the autoarchive options are not scalable and are often easily misconfigured.  Sometimes creating unexpected results when autoarchiving. Alternatively, manual archive really just wastes employee time and corporate resources.

Finally, a data loss and security nightmare.  These are portable files that can be copied and taken offsite, and in our security conscious culture of today this is just NOT ok.


Exchange on-premises preferred architecture allows for affordable disk options.  Even if you choose to go with alternative deployment options such as virtualized on SAN disk cost will not have the same level of consideration as it once did 20 years ago.

If your organization is leverage on-premises Exchange or Office 365 Exchange online there are suitable built in archiving options that can be leveraged.  There are also some really great 3rd party products that will do a great job as well.

Security today is more important than ever, so leaving corporate data in portable PST files is no longer an acceptable solution.