If you want to import OST files into Thunderbird then we recommend you to opt BitRecover Import OST to Thunderbird as this software updated with advanced functionality to make it reliable for all professional and individual user. This software specially optimised with advanced algorithm to offer inbuilt modern filter feature to easily manage OST data without losing any information.
For more information:
https://www.bitrecover.com/blog/open-ost...underbird/
For a smoother experience, I recommend using the
Aryson OST Converter Tool. It’s a reliable and user-friendly utility that directly converts OST files into MBOX format, fully compatible with Thunderbird. You don’t need Outlook installed, and it maintains folder hierarchy, email formatting, attachments, and metadata. Plus, it supports all types of OST files, including corrupted and orphaned ones.
The ideal option is
Advik OST Converter, which can directly
import OST to Thunderbird. Take advantage of the importing process by uploading additional OST files without size restrictions. Before converting, You may preview OST elements using a handy preview tool. You may be confident that the program will keep your files intact and structured by maintaining folder hierarchy and data uniqueness. You can download its free demo version to check its working procedure.