“How can I open a PST file without Outlook?”

Opening a PST file without Outlook.

Thanks to Microsoft’s release of the PST file specification to software developers, its now possible to open PST files without Outlook.
Microsoft Outlook email client is the original source of billions of .PST files in the world. For years, their PST format was a closed secret. But in 2010, Microsoft began publishing parts of the PST specification. This has allowed software developers to create tools such as PST Viewers (often referred to as Outlook Viewers) that can give you access to your emails, even if you don’t have Microsoft Outlook installed on your computer.

If you need to open a PST file, why not just install Outlook? That is certainly a fair question, because Outlook is an excellent email client (although it can be a bit pricey). I have used Outlook for years, and I love it.
But there are occasions where its easy to envision the usefulness of a PST viewer:

If you used Outlook at work, but you don’t have it at home and you wish to have access to your work email.  
If you have moved on to a different email client, like Lotus Notes or Thunderbird, and its important to you have access to your email history, then a Outlook Viewer may be the right choice.
If you have several PST files you need to search immediately and you don’t have days to wait for Outlook to index your files, a PST viewer can give you quick access to your emails.

How do Outlook .PST Viewers Work?

Most Outlook viewers are fairly straight forward and function in a manner similar to Outlook.  When the viewer starts, you can select a PST file from a list.  This will cause the Outlook Viewer to examine the file and present a list of emails messages, which you can sort by different criteria.
Main menu of an Outlook Viewer software application for reading .PST files.
PST Viewer Pro menu showing emails

The Outlook viewer shown here is Pst Viewer Pro by Encryptomatic LLC. A free trial can be downloaded for the PST Viewer website.
Outlook Viewers will vary in quality
and the features they offer. An advanced reader like PST Viewer Pro will allow
you to convert email messages to PDF and other formats. You’ll be able to reply
to messages using your existing email client. It’s often possible to do a deep
search of the PST file to find important emails.  They should give you full access to the file
attachments and embedded images with the email message.  You should be able to expand an email to a
full screen view by clicking on it.

Although there are some readers on
the market that are free, be careful that you don’t install a viewer that tries
to install spyware on your computer. Free viewers may just provide the most
basic features and may require you to view commercial offers during the
installation process. They may try to recoup their costs by installing software on you computer that serve ads, or prospect for other services they can sell you.

A paid commercial Outlook viewer should not behave that
way, if the developer is credible.  Also
be certain that the installation package is “code signed,” by the developer. You can
tell if its signed because when you start the installer, Microsoft will
announce who the developer is. An unsigned installer will be from an “Unknown”

Outlook Viewers are helpful tools
that make your emails more accessible, especially in environments where Outlook
is not installed or when it’s not convenient to wait for Outlook to complete
indexing of the PST files. 
The best way to experience the
benefits of an Outlook viewer is download a free trial and see for yourself if
it is a good fit for your needs.