Yes, there are several reliable tools and software available for repairing PST and OST files in Outlook. Below are some of the most commonly used options:
1. Inbox Repair Tool (ScanPST.exe)

Description: This built-in tool from Microsoft is designed to repair minor corruption in PST files (and, to a lesser extent, OST files).
Usage: Located in Outlook's installation folder, ScanPST.exe scans and attempts to fix issues by identifying and correcting minor corruption in PST files.
Limitations: Effective only for light corruption or file errors. It may struggle with larger or more severely damaged files.

1. Goldytools OST to PST Repair Tool

   Description: Goldytools offers a robust PST repair tool that can handle severe corruption and recover lost or deleted emails and mailbox items.
   Features:
   User-friendly interface.
   Supports large PST files.
   Recovers emails, attachments, contacts, calendars, and more.
   Can split or compact PST files to avoid future corruption.
   Dual-purpose: Converts OST files to PST.
   Additional Capabilities: Offers extensive recovery options for multiple mailbox items.

2. Vartika Outlook PST Repair Tool

   Description: A powerful third-party tool for repairing severely damaged PST files with high recovery accuracy.
   Features:
   Repairs large and heavily corrupted PST files.
   Recovers deleted emails and other mailbox data.
   Allows recovery in multiple formats, including PST, EML, MSG, etc.
   Supports encrypted PST file recovery.
   Limitations: The free version has limited data recovery capabilities.

3. SysVita Outlook PST Repair Tool

   Description: Known for its efficiency in handling severely corrupted PST files, SysVita is another reliable option for data recovery.
   Features:
   Recovers emails, contacts, calendars, tasks, and more.
   Saves recovered data in multiple formats, including PST, MSG, EML, DBX, and MBOX.
   Limitations: The free version is restricted in functionality.

4. vMail Outlook Repair Tool

   Description: A highly regarded tool for repairing both PST and OST files, known for its high success rate with severely corrupted files.
   Features:
   Recovers all mailbox items, including emails, contacts, calendars, etc.
   Can handle large PST files that exceed the 2GB limit.
   Supports both PST and OST file repairs.
   Limitations: Full functionality is available only in the paid version.

5. KDEtools Outlook PST Repair Tool

   Description: A versatile tool designed to repair PST files and recover mailbox items from heavily corrupted files.
   Features:
   Recovers emails, contacts, calendars, journals, etc.
   Saves recovered data in multiple formats.
   Includes a preview option before saving the recovered data.
   Limitations: The trial version allows only limited data recovery.

Conclusion:

These tools vary in capabilities and are suitable for different levels of corruption. For basic repairs, ScanPST.exe (Inbox Repair Tool) is often sufficient, while for more complex or severe issues, third-party tools like Goldytools OST to PST Repair Tool or vMail Outlook Repair offer more advanced recovery options.
https://www.goldytools.com/outlook-pst-repair.php