If you want to open an Outlook OST file in Outlook and the original Exchange account is not available, then eSoftTools OST to PST Converter software is the best option. This software reads the data from the OST file and converts it into an Outlook-compatible PST format, which you can easily open in Outlook. The tool safely extracts emails, contacts, calendars, tasks, and attachments without any data loss. Its simple interface makes it easy to use even for non-technical users, and it supports all Outlook versions, making accessing your OST file fast and secure.