Nonetheless, you can reduce PST file size by using Outlook’s ‘Archive’ or ‘Import/Export’ option. However, Outlook does not provide any inbuilt utility or feature to split a large-size PST file. Split the PST file: To manage large-sized PST file, you can split it into multiple small-sized PST files.You can manage your large-sized PST file manually by following different ways, as mentioned below: Also, you must know ways to manage an oversized PST file to prevent it from getting damaged or corrupt in the first place. In case the PST file gets corrupted, you will not be able to access the PST file and its contents unless the file is repaired. An Outlook PST file exceeding the 50 GB size limit is prone to corruption and may result in ‘ cannot open the PST file’ error. Outlook 2010, 2013, 2016, and 2019 support PST files of a maximum of 50 GB.