Outlook is the most widely used email client in Windows world. However, Outlook PST data files are also prone to corruption. Why? Below we will analyze the reasons and corresponding solutions.

1. Microsoft does not provide an effective way to prevent the PST file corruption

The first and most important is that Microsoft does not provide an effective way to prevent the corruption, as follows:

  1. The PST file format itself does not have an anti-corruption feature, such as a recovery record as in WinRAR .RAR archive format or torrent page as in SQL Server .MDF database. With a recovery record or torrent page, when a portion of the data are corrupt, it is easy to recover them and reduce the chances of data loss by 90%.
  2. The PST file is easy to get corrupted when the file size increases, and there are no mechanism to prevent this automatically. Outlook will not use multiple files to store the data automatically when the file size is large. The user needs to do it manually. And of course, most of the users will not notice this. The only related feature in Outlook is prompting the user to archive old emails, but this feature does not pay attention to the file size.
  3. In Outlook, there is no auto-backup feature for PST file. If Outlook had such a feature, then if a PST file is corrupt, even if it cannot be recovered, one can restore to an early backup version, which will contain most of the up-to-date data if the backup is performed every week.
  4. Microsoft does provides a free PST file recovery tool called scanpst, accompanying with Outlook. However, it can only fix PST file with minor corruptions. If the damage or corruption is severe, then scanpst will fail for most of the cases.

2. Many people are Abusing the PST file:

Outlook is so popular that there are so many people use it every day. And many are abusing the PST file which makes it prone to corruption:

  1. Nowadays due to the increase of the emails and other personal data, the size of PST file increase dramatically. From several GBs in the early days, to more than 20GB or even 50GB. The larger is the PST file, the more easier it will get corrupted. A good practice to manage large data is to split them into several smaller PST files, for example, archive old emails to archived PST files, to make sure each PST file size <= 10GB, instead of using a very large PST file.
  2. Someone will shutdown the computer when the PST file is still opened by Outlook, which will also cause corruption.
  3. Someone will store large PST files on network drive, which is not recommended since PST file itself is not designed for this. And it is easy to cause corruption when accessing the PST file via network.

More detailed info about good practices to prevent PST file corruption can be found at https://www.datanumen.com/prevent-pst-corruption/

How to Fix the Corrupted PST files:

If PST file corruption occurs, then first you can try free scanpst, since it is the official tool provided by Microsoft to fix corrupted PST files, and it is free. If it does not work, then you can try DataNumen Outlook Repair.