OST to MBOX Conversion Methods for Outlook Data Migration

To convert an OST file to MBOX manually, first export the OST data to a PST file using Outlook’s export feature. Then, set up an IMAP email account (like Gmail) in both Outlook and Thunderbird. Move the emails from the PST file to the IMAP account in Outlook, allowing them to sync to the server. Thunderbird will then download these emails in MBOX format automatically. This method requires Outlook and an IMAP account but effectively converts OST to MBOX without third-party tools.