To Import OST file to Office 365 account manually, you first need to convert the OST file to a PST file using Microsoft Outlook's export option. Then, use the Office 365 Import service to upload the PST file to a mailbox. This process involves multiple steps, including exporting data from Outlook, preparing the PST file, uploading it to Azure storage, and then mapping it to Office 365. The manual method can be time-consuming and error-prone, especially for non-technical users. It may also result in data integrity issues if the OST file is corrupted.

Alternatively, using Migrate Cloud Data OST to PST Converter simplifies the process. The tool converts OST files directly to PST format, maintaining data integrity. You can then import the PST file to Office 365 without any hassle. It provides a user-friendly interface and supports bulk conversions, making it a more efficient and reliable solution for importing OST to Office 365 accounts.