The simple and best way to convert MS Outlook OST file to TXT is to use a professional tool like Aryson OST to PST converter. This OST to PST converter is the best tool to convert MS Outlook OST files into PST, DOC, DOCX, HTML, MHTML, PDF, TXT, etc. This tool maintains the data hierarchy throughout the conversion process. However, this tool is the best tool that migrates the OST file to a number of email clients such as Office 365, Thunderbird, Yahoo Mail, Opera Mail, Hostgator,  etc. This tool maintains the data hierarchy throughout the conversion process. It doesn't matter it easily converts single and multiple OST files at the same time. This tool is compatible with all versions of Outlook and Windows. Many other features come with this tool. 

Steps to convert MS Outlook OST file to TXT

- Download and install the OST to PST Converter.

- Then select the OST file to convert and click on the next button. 

- After this select the OST file/folder to preview.

- Now select the file format to convert. 

- Then select the path to save the resultant file. 

- Lastly, click on the convert button to start the conversion process.