To Import OST file into Outlook, you'll need to first convert it to PST format since Outlook doesn't directly support importing OST files. The manual process involves using the "Import/Export" feature in Outlook, where you can open the OST file in Outlook on the original account, export it to PST format, and then import that PST file into another Outlook account. However, this method requires the original account setup and often doesn't work if the OST file is orphaned or if there are access restrictions.

For a more streamlined approach, the Migrate Cloud Data OST to PST Converter Tool offers a reliable solution. This tool simplifies the process by directly converting OST files to PST without needing the original Outlook account. It also preserves email structure, attachments, and metadata, ensuring a seamless import into any Outlook account. This tool is especially useful for users dealing with corrupted or inaccessible OST files, making it an efficient choice for hassle-free OST to PST conversion.