To open the ost file in Outlook 2019, the operators will have to convert the ost file to pst file format.
Get the easy and powerful solution by using the SysInspire Software ost to pst Converter to easily convert Outlook ost mailbox to pst file.
install the SysInspire ost to pst Converter onto your system.
Click on Open from the screen and then click on Browse.
Select the ost file which you want to import into pst format and click on Open.
Select the suitable scanning process.
Now ost files details are displayed and other options. Click OK to start the scanning process.
You can now check the get a sneak peek of their mailbox content. Select the mailbox folders which you want to save into the pst file else you can go for total file conversion.
Now, browse to select a location for the new pst file and click OK to start the conversion.
The ost to pst conversion is being done on your System.
First, you can use this application with the demo version. You can avail all its features and then go for the paid version.
More info:- Search on google SysInspire OST to PST Converter Software