If you are looking for a software to compress PST files then you can try Aryson Outlook PST Compress Tool. This tool is the most reliable and secure to compact the oversized PST files without needing to install the MS Outlook on your local device. It supports all versions of the Windows OS and Outlook and PST file can be opened with Outlook 2016 and later versions without any issues. Users can removes the attachments from PST files to reduce their size. The tool offers an easy and simple user interface.