Outlook has two file formats; OST and PST. If users work offline on Outlook, the file so formed saves in OST format. OST is inaccessible, and to access it, one needs to convert it to PST. And so, the importance of PSTs increases. 

 
On the other hand, there are several automated tools available to convert OST to PST. One of these tools is Weeom OST to PST Converter. 
1-It converts healthy as well as corrupt OSTs to PST. 
2-Preview option is available for data before the conversion
3-It has many user-oriented features, such as it allows multiple OST addition,  split PST,  maintains data integrity, recovers deleted items, and so on.

Use Weeom OST to PST Converter tool in a free trial version before paying for it. This tool processes the first 50 items per folder in its trial version.

For more info, visit:- https://www.weeom.com/ost-to-pst-converter.php