How to deal with an orphan Outlook .ost file
Many people mistakenly make copies of an .ost file associated with an Outlook email account not realizing that there is absolutely no value in doing so.
What is an “orphan” OST file?
An orphan OST file is one that has become separated from the Outlook profile/email account that was originally used to create the file. Most common cause for this is someone making a copy of the file in hopes that it will provide them with a backup of their data.
An OST file is a mirror image of what is contained on the server for the associated email account. In the case of an IMAP account (Outlook ‘2013/’2016) this only involves email folders. Other data, such as contact/calendar items are stored in the OST file with the additional label “This Computer Only”. For Outlook.com/Exchange based accounts, all data is sync’d with the server including contact/calendar items.
Recovering OST data
The only way to recover data from an orphan OST file is to use a 3rd party OST2PST conversion program. This would be required if the OST file was associated with an IMAP/Exchange account that is no longer accessible or in the case of IMAP, the requirement was to recover the contact/calendar data even if the Imap account could still be accessed.
There are many 3rd party OST2PST conversion programs – one of which is OST2 from the 4Team folks which from our tests is one of the most complete ones available in that it supports custom forms and user-defined fields which many of others did not (at least not at the time the programs were tested)
Category: Outlook - How To
