Outlook PST (Personal Folders File) file size limitation is the most common reasons that can corrupt the file. Outlook 2002 and earlier versions data files should not be more than 2 GB in size or otherwise, can attain chances of being corrupt. The oversized PSTs get corrupt in such a way that even the Inbox Repair Tool (Scanpst.exe) cannot repair them. You need to crop them first that causes emails to delete. The safe solution to retrieve data from such files is to restore from backup or to use a PST Recovery utility.
To elaborate such problems, consider you try to send a quite large attachment with an email. The email sending process starts, but you terminate it after it runs for a considerable amount of time. At next start, when you open Outlook, you find PST showing corruption symptoms. You may receive different error messages in this support. The PST file size grows to much larger value than before, which probably indicates that the attachment being sent still contributes to the overall PST size.
Cause
Outlook PST is a database. So, once you add any item to the file, the overall file size increases by item's value and doesn't wipe out. The increased PST file size above 2 GB can result into PST corruption.
Solution
To resolve the above issue, you should consider these suggestions:
1-Try to compact the large PST. For this, click 'Data File Management' in 'File' menu. Choose your 'Personal Folder' and click its 'Settings' option. Then, click 'Compact Now' in 'General' tab.
2-If the issue persists, it might be due to PST file corruption. To repair it, run Inbox Repair Tool (associated with program file- Scanpst.exe). You need to locate this file first, launch the tool, and specify the affected file name and path while making sure to include hidden and system files.
In case PST remains corrupt, you need a more powerful solution for Microsoft Outlook Recovery. The third-party PST Recovery tools are available that can repair a corrupted PST and restore it with original contents and view.