[silasstem]

I have an old OST file, which does not work. I want to Convert OST to PST in Outlook 2013/ 2016/ 2007/ 2010 with all emails, contacts, calendar, task, notes etc. when Exchange Server goes to be down. 

May you help me to suggest right solution that export mailbox from an OST file to PST format.

[kylesen]

I think you should go with OST to PST Converter tool to convert accessible and non-accessible OST files into PST. It has a free trial version as well which helps to know about this tool features and working ability.

Visit here more info: http://www.outlookconverter.net/ost-to-pst/

[Ethan Jakson]

If you want to convert OST to PST file format, you can take the help of an OST to PST converter which is reliable for this conversion. For more info, you can take the help of this blog. I found it over the internet and found useful, that's why I am sharing it here.

https://msoutlookhelp.com/blog/perform-c...s-outlook/