Microsoft Outlook stores mailbox data into PST file format while Mozilla Thunderbird support MBOX files in handling mailbox data like emails, contacts, calendars, notes, etc. Several times users switch their email clients from Outlook to Mozilla Thunderbird. In this situation, Users can not access or open Outlook datafiles until or unless they convert them into MBOX file format because as you know Thunderbird supports MBOX file format.
For effortless and easy way to import Outlook data files to Thunderbird is to utilize a reliable PST to MBOX Converter software. It is capable to recover and transfer entire deleted or deleted mailbox data of Outlook to MBOX file format. There is no restriction in this software. You can import big sized PST files to MBOX along with emails, contacts, calendars, attachments, tasks, notes, etc. The software comes with wide range of features and user-friendly interface so that users can easily and safely import Outlook emails to Mozilla Thunderbird.
Read more- https://www.zooksoftware.com/pst-to-mbox/