OST and PST belong to the same email client, MS Outlook for Windows, but they don't support each other. When it comes to accessing OST data on PST, the conversion of OST to PST is the one and only way. PST is an upgraded file extension, store data up to 50 GB. Users can consider bulk data migration from OST to PST.

Since your goal is to get custom conversion support, there are two ways to achieve it.

Manual Method- Import & Export Mailbox as PST File

The manual method is effective. Make sure you are well connected to the Exchange Server and have pre-installed MS Outlook.

1. Open your MS Outlook, go to the File menu at the top left corner

2. From the dropdown option, choose Open & Export and then Import/Export

3. The Import and Export wizard will open from where select Export to a file option in multiple options and click on the Next tab

4. In the Export to a File wizard, select Outlook Data File (.PST) and press Next

5. Now, select the required folder you want to export from here and click the Next tab

6. Select the appropriate file location and from multiple options, choose to Replace duplicates with items exported, and finally press the Finish tab.

Using an Application

Do you think the manual method is easy? If yes, go ahead with the method else install an OST to PST converter. The Softaken OST to PST Converter is one such valuable application to export data. The app is capable of exporting not just one but also multiple OST files to PST. Users get custom conversion support because the application can export only selective folders of OST to PST. They are flexible to export either entire data or a few specific folders of OST to PST.

https://www.softaken.com/ost-to-pst-converter

SysInspire OST to PST Converter Software, that will instantly export all inner mailbox components from corrupt NSF file to multiple accessible file types such as- PST, EML, EMLX, MSG, HTML, etc. Through the application, you can smoothly make the conversion of selective single or multiple items of NSF file to another accessible file format by just applying some simple conversion steps.

Get More Info:- Convert OST to PST

Users can also try VOOK OST to PST Converter for the instant conversion of the OST emails to PST format in no time. This utility is the best place to easily switch the emails to the required file formats. It ensures the users about the safe conversion of the data files without losing a bit of information. Users can efficiently export the bulk emails in the batch mode with all the attachments embedded in it. It preserves all the email properties and data integrity of the emails intact even after the conversion process.

The best OST to Outlook Converter is capable enough to split the large OST emails into smaller ones and can merge the fikes in a single PST folder after the migration process. It is supportable with all the MS Outlook editions such as Outlook 2019, 2016, 2013, etc. A FREE TRIAL EDITION of this tool is also available that avails the users to export 25 OST emails to Outlook format without any restrictions.

Read more details at:- http://vooksoftware.com/ost-to-pst/

OST can be converted through the utilization of third-party software which can be utilized by all users without any error. You can use the best tool that is the SoftWeak OST Converter software. This advanced and perfect software can easily convert bulk OST database through a single processing way. You can understand its working p[rocedure through the help of its Free Edition which can be utilized by any user to convert OST files into PST with some limitations.

Download For Free: https://www.softweak.com/converter/ostconverter.html

There are many tools available that convert OST file to Outlook PST format. But I personally like SysCurve OST Converter. The tool quickly acts on the OST file and convert OST to Outlook PST, MSG, EML, MBOX, and other file formats. By using this tool, you can also perform selective conversion. The software comes with a free version, which allows users to save the first 20 items from each folder.

To know more about this tool, visit: https://www.syscurve.com/blog/how-to-convert-ost-to-pst.html

There are two ways to convert Outlook OST file, either use the free manual method or use expert suggested and verified utility. 

• You should use only digitally signed utility
• Suggested by experts and professionals 

MVP Recommendation is to use QuickData OST to PST Converter Software

You can also follow the free manual method (but the steps are not verified and recommended)

Read the Informative Blog to understand Free Manual Method to Convert OST to PST Format