If the Mozilla Thunderbird not responding then you can use the most advanced featured software that can solve this problem, that is SysInspire MBOX to PST Converter tool. This software can auto load your Thunderbird file and fix all its errors then start to convert it into Outlook PST. This software cannot damage any element of the MBOX file like Contact, Calendar, Background, Photos etc. if you want to use this software then you can use it without any technical knowledge because of its advanced feature or user-friendly interface. 

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