Time to finally get rid of those Outlook PST Files with Office 365, PST Migrator, and FSLogix

Posted by Chad Baker on Sep 18, 2018 11:42:19 AM

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PST files, otherwise known as Microsoft Outlook data files, have been in-use for over 20 years.  Once the redeemers of under-sized Exchange mailboxes, they now create headaches for IT storage, security, messaging, and support teams.

Why Now?

With the increased use of Office 365 to offload the management and storage of Exchange email with 50 – 100GB primary mailboxes as well as unlimited online archive space (depending on license level), the argument for keeping PST files and their risks makes little to no sense for most organizations anymore. The Exchange Online mailbox storage is included in the Office 365 licensing whether it’s used or not, so taking advantage of it is the best choice both operationally and fiscally.

However, in the past, migrating the data out of PST files back into Exchange mailboxes was a manual and time-consuming task that most IT departments did not want to take on, and if they did, that just moved the email data back to expensive storage in the datacenter.

With Outlook Cached-mode, better user experience was provided while still centrally managing email data. Enter Outlook in non-persistent VDI and Terminal Server/XenApp deployments where Outlook Online mode (no caching) was used since the computer resources could be in the same datacenter as the Exchange servers. To take advantage of email in Office 365 with good user performance, Outlook online mode can’t be used as now the email data is up in the Azure cloud, no longer next to our compute resources.

LAE Software’s PST Migrator + FSLogix + Office 365

To take advantage of Office 365 and avoid the above-described pitfalls, LAE Software’s PST Migrator with FSLogix is a winning combination to finally put to rest PST files in a high-performance Office 365 solution.

  • PST Migrator is an ultra-lightweight, clientless software tool that finds PST files, automatically migrates them up to Office365 in the background, then removes them once it’s done. No infrastructure or install is needed and scales to any size environment. Whether you’re planning to go to Office 365, are in the process of doing so, or have already completed your migration, PST Migrator can deal with the PST files in your environment to finally be rid of them!
  • FSLogix O365 Containers then puts the icing on the cake, as in high performance Outlook user experience for VDI and Terminal Server/XenApp environments. By seamlessly allowing for Outlook Cached-mode to be used in non-persistent desktops hosted apps, FSLogix makes migrating to Office 365 an easy decision.


The support overhead varies per organization and by the amount of data stored in the PSTs.  For more concrete reasons to move to Office 365 and get rid of PST files in your environment, consider the costs of keeping them around:

  • Data recovery of crashed disk drive:
  • Lost productivity from lost data:
    • Similar to the risk of disk drives failing, if a disk cannot be recovered, or lost, people need to recreate the data lost.
  • Data breach risk:
    • The Ponemon Institute has estimated the average cost per record of a data breach by industry. For instance, healthcare average cost is $380/record lost.
  • Litigation risk:
    • During litigation many cases are lost from the discovery of damaging data in PST files. Much harder to estimate but a real risk.
  • Support Hours:
    • Support groups like tier 1 helpdesk and deskside support spend many hours dealing with corrupt PSTs. When PSTs are stored on network shares the problem is compounded because PSTs are easily corrupted (and technically not supported) on network shares.
  • Backup Costs:
    • PSTs are rarely backed-up unless they are stored on network shares. When they are backed-up the costs can increase greatly because PSTs are large files that do not de-duplicate.  Additionally, every time Outlook is opened, the PST is identified as needing backed-up again. 
  • Storage Costs:
    • PSTs can be hiding in many areas of enterprise storage. Most commonly on NAS systems but also within virtual machines.  High performance enterprise storage costs can be high.  Often the high cost is mitigated by data reduction technologies like deduplication and compression.  Since PSTs are already compressed, they cannot be de-duplicated or compressed. 

Since Office 365 offers large mailboxes and an online archive, PST Migrator automates the finding, migrating, and removal of PST files, while FSLogix maintains the on-prem Exchange performance once in Office 365, the need for PSTs no longer exists and the time is now to deal with them.

Topics: Office 365, Outlook, PST Migrator

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