https://blogs.msdn.microsoft.com/interoperability/2010/05/24/two-open-source-projects-to-facilitate-interoperability-with-outlook-pst-data-files/ :

Microsoft announced the availability of two new open source projects that complement technical documentation recently released[1] for Microsoft Outlook Personal Folders (.pst).

available on Codeplex.com under the Apache 2.0 license are the following:

* The PST Data Structure View Tool (http://pstviewtool.codeplex.com/) is a graphical tool allowing the developers to browse the internal data structures of a PST file. The primary goal of this tool is to assist people who are learning .pst format and help them to better understand the documentation.

* The PST File Format SDK (http://pstsdk.codeplex.com/) is a cross platform C++ library for reading .pst files that can be incorporated into solutions that run on top of the .pst file format. The capability to write data to .pst files is part of the roadmap will be added to the SDK.

The open source SDK is meant to be cross-platform. It's written in C++. That said, for Java developers having Java librairies will help as well. The PST Data Structure View Tool is also very useful to understand the PST specification (which is available under the Open Specification Promise).

[1]: https://blogs.msdn.microsoft.com/interoperability/2010/02/19/new-office-documentation-now-publicly-available/

Open Specification Promise [...] will allow anyone to implement the .pst file format on any platform and in any tool, without concerns about patents, and without the need to contact Microsoft in any way.

* * *

Other tools to work with PST in Sisyphus:

1. https://packages.altlinux.org/en/Sisyphus/srpms/libpst
2. https://packages.altlinux.org/en/Sisyphus/srpms/libpff
3. https://packages.altlinux.org/en/Sisyphus/srpms/java-libpst