Did you know that Microsoft changed its retention policies for Outlook Data Files (PST File type) in August 2021? Since the announcement of the change, there is much confusion in the community about the impacts of the change and what to do to avoid unexpected data losses. In this blog post, we will help you understand the change and how it will impact your email backup.
What is the change?
Starting August 16, 2021, Microsoft introduced new retention policies for Outlook Data Files (PST File type) Versions that limit the number for PST versions retained to 30 in 30 days.
Outlook constantly updates PST files, generating multiple versions which leads to storage being quickly consumed by the multiple versions of the PST file for extended periods. With the policy change, if you make a change to a PST on November 1st and thus create a new version of the PST, the version will be deleted on December 1st with no way to recover. If you make no changes to the PST file then on the 31st day after your last change that file will be the only copy retained, all previous versions will have been deleted.
This will NOT remove the PST from your OneDrive or SharePoint Online, just the copies retained after a change to the PST.
What is the reason behind the change?
According to Microsoft, the PST version retention policy changes are being introduced to address concerns around storage impact of PST versions and will ensure PST file versions no longer consume storage for extended periods. When PST files are uploaded on OneDrive for Business and SharePoint Online team site document libraries, Outlook constantly updates PST files generating multiple versions. This leads to storage being quickly consumed by the multiple versions of the PST file. With these changes the service will always retain a minimum of 30 days’ worth of PST versions.
How will you be impacted by the change?
The answer depends on your PST file backup practice.
1. Scenario 1 - You currently do not upload PST files into OneDrive and/or SharePoint. This change has NO impact to you. Keep using local copies of PSTs and backup your endpoint at least daily.
2. Scenario 2 - You have executed a SharePoint Online Management Shell cmdlet before Aug 13, 2021. You are exempted from the change. However, keep in mind it is NOT best practice to have PST files that are saved to your OneDrive or SharePoint Online connected to your Outlook client. There are too many ways that the PST could become corrupted by bit shifting, transmission delays or signal drops.
3. Scenario 3 – You still use OneDrive and/or SharePoint to back up your PST files. This is where the change will have an impact on you because PST versions older than 30 days will be permanently deleted. You should consider educating your users to stop using OneDrive / SharePoint to back up your PST file:
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To prevent uploading .PST files from the OneDrive sync app, read Block syncing of specific file types.
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To move .PST files out of OneDrive, read How to remove an Outlook .pst data file from OneDrive.
The importance of email backup can't be overemphasized. If you have any questions and concerns about your current email backup practices, contact Blair Technology Solutions today.
