Outlook’s PST File Format Is Finally Open To Developers


One of the major complains from developers regarding Microsoft’s popular email client, Outlook, was that the Personal Folders (.PST) file being closed. Since every data is stored inside the PST file and it could only be accessed via Outlook or Windows-focused APIs, developers who wanted to read or write data to it were facing difficulty.

OutlookAs promised by Microsoft, today they have released a set of tools (two opensource tools) that will help developers easily read and write data to the PST file. It will also help in making the PST file compatible with other email platforms, don’t be surprised when Mozilla Thunderbird starts supporting the PST file.

The names of the two tools are PST Data Structure View Tool and PST File Format SDK. They are available on Codeplex and can be grabbed by visiting the links below.

The .PST file has been opened under Microsoft’s Open Specifications Promise, which allows, “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”.

This looks like a major step from Microsoft that will be highly appreciated by the opensource community. Now we just need to wait for a few months before seeing a fluid of apps by 3rd party developers that are based around the popular PST file format.

Watch the video at Microsoft’s Interoperability blog for more details on these two projects by Daniel Ko, development manager in the Outlook team.