Users face problems when they try to access the ost file by copying it to another system, or when they try to access exchange OST file which belongs to other company in computers. They are shown an error message displaying:
"OST file that you are trying to access cannot be opened in MS Outlook Application"
The reason behind this inaccessible OST file error as trying to open an Orphan OST file.
Now the question is What is Orphan OST file? – As, OST is an exchange offline folder, generally a copy of mailbox on an Exchange server. Whenever this mailbox is not available on the server, the file is called Orphan OST file. There are various reasons that makes OST file orphan. Some of it are discussed below
So, when you try to open orphan OST file, an error message is reported because of orphan OST file.
You cannot read, view, or open exchange OST file in Outlook if its get orphaned. In such cases, it is necessary to fix orphan ost file and implement a process which can extract data from the orphan ost file to accessible file format. Since, there is no manual procedure available to do this task you require to use a third party software application such as OST Recovery. It will help user to change the inaccessible OST file to healthy format file which can then be accessed very easily in Outlook.
Regularly Create Backup of your OST file, it will help you in unforeseen incident discussed above. You can also try to find and save MAPI address of your Outlook account.