MS outlook is a popular text messaging tool used for sending and receiving text messages or emails. It has several user friendly features like large mailbox size, import export management, fast delivery of emails, multiple file attachment supports, contacts and many more. You can link MS outlook with POP3/IMAP email server such as MS exchange. One can also connect his outlook mailbox directly with internet. MS exchange server provides interface to all outlook users of a domain network. Email records of the outlook user account are stored in two files i.e., OST and PST files. OST or offline storage table is a temporary file that stores all emails of single outlook user account. When internet services in outlook mailbox is interrupted or lost, all emails of that account is saved in an offline file or OST file. When MS outlook is reconnected with internet, all mail communication of the outlook user during offline period is transferred from OST to PST file.
However, many factors prevent OST files to send emails in outlook PST files. These factors are:
- Intrusion of virus and spyware code through exchange server
- slow internet connection
- Hard disk error
- Fault in networking cable
- Crash of exchange server
OST file may be damaged due to any of the above mentioned reasons. When OST files of exchange server become corrupt, all outlook mailboxes stored in these files also become corrupt. In that situation, users shall not be able to use their outlook account. You shall get different error messages while trying to open your outlook mailbox from the corrupt OST file:
- Cannot open your default email folders. The file xxxx.ost is not an offline folder file
- The file OST_File_Path\outlook.ost is already in use by the maximum number of applications
- Unable to expand the folder. The set of folders could not be opened
- OST file cannot open Outlook
MS outlook program is equipped with inbuilt recovery tool scanpst.exe to repair both PST and OST files. Scanpst.exe is saved in different location of user system. You can find the tool either from the search box of window start menu or through manual search. The inbuilt OST file recovery tool of Outlook will retrieves emails and email folders of outlook mailbox from the corrupt OST file. All retrieved items are saved by the scanpst in new OST file. However, scanpst.exe fails to retrieves emails in its exact form from the corrupt OST files. Earlier versions of the MS outlook restrict the OST and PST file size up to 2 GB only. The OST file recovery tool of MS outlook also fails to repair the oversized OST files. Scanpst.exe is suitable for minor corruption issue of OST and PST file. It cannot be used to fix the corruption of large or several outlook mailboxes.
Another way of OST file recovery is making backup of OST files before corruption using Window backup archive creator or any third party convert OST to PST software. You shall be able to retrieve outlook mailbox items from the backup copy in case loss of original files.
If you don’t have backups of OST files or OST files are severely damaged, then use proficient third party email recovery software. The third party OST to PST utility retrieves emails from the corrupt OST file and saves in PST file.