Final Reminder: Adjusting Version Retention for Outlook Data Files (PST File Type) on One Drive and SharePoint
As communicated in MC256835 (May ’21), starting August 16th 2021 the service will retain 30 days worth of versions for any PST files stored OneDrive for Business and SharePoint Online team site document libraries. This change will prevent cases of previous versions of PST files quickly consuming available storage. The change will only impact previous versions of PST files stored in your document library storage.
As best practice PST files should not be uploaded on OneDrive for Business and SharePoint Online team site document libraries due to the impact on storage and network bandwidth. When PST files are uploaded on OneDrive for Business and SharePoint Online team site document libraries, Outlook updates PST files generating multiple versions which leads to storage being quickly consumed by the multiple versions of the PST file.