Most of the users of MS Outlook are quite aware of two types of file formats i.e. OST and PST files. PST files (Personal Storage Table) are the main storehouse of all the data stored in Outlook whereas OST files (Offline Storage Table) contains the replica of data stored in Exchange server. OST comes into existence when the cached mode is enabled from Outlook allowing user to work offline without Mail server. Any changes made will get itself synchronized when connected with the Exchange Server. The blog will be discussing the reasons why we need to convert OST files to Outlook PST file.
Need of Conversion from OST File to PST
The main reason why users prefer to convert their Exchange OST mailbox to PST file is the several issues of OST file that makes the OST file inaccessible or corrupted. Some of the causes that lead to the conversion of OST to PST file are as follows:- Issue of Exceeding OST Size Limit
Size limit of OST file varies with different Outlook versions. In Outlook 2007, size limit supported was 20 GB, which was increased to 50 GB in 2010/2013 versions. Usually, the maximum default size limit is set to 20 GB, which is why performance of Outlook slows down when it reaches or exceeds this size limit. - Orphaned State of OST file
Each OST file is bound to particular Exchange Mailbox and any modification made is continuously synchronized to Exchange Server. When the Exchange Mailbox is dismounted/deleted from the server, the OST file will become inaccessible leading to orphaned state. - Synchronization Problems
It arises if there is any interruption while the OST file is being synchronized with the Exchange Server. Since the OST file is encrypted, decryption key of the Outlook profile needs to be matched with the one in Exchange Server. If it does not, OST file will face synchronization problem making file inaccessible. - OST Bound to MAPI Profile
Since OST file is bound to a particular MAPI profile, its access can be only done when the user log in and authenticate using the profile that was originally used to create an OST file. In case of authentication failure, client will restrict user to open Exchange OST file and its contents. - Corrupted OST File
OST file may be corrupted due to power failure during synchronization, virus attack, improper handling of OST file, damaged hard drive/local storage where the OST file was stored, etc. The OST file in corrupted state may lead to inaccessibility and loss of contents in it.