Download OST File to Thunderbird MBOX Converter too is one of the best conversion tools. This software This software import OST to Thunderbird will convert the entire email messages from inbox, sent items, drafts, outbox, etc along with all attachments. During the conversion process software maintains all the folder structure & saves MBOX files with same folder structure. It allows users to converts multiple OST files into MBOX files in just single process. It has very simple user friendly graphical interface, so anyone easily handle it software without any problem. The software supports to operate on all Windows OS. It also supports all latest & below versions of software. Try free demo version free of cost.