To Transfer Outlook Emails to Thunderbird manually, you can use the IMAP method. First, configure your Outlook account as an IMAP account. Then, create a Gmail account or use an existing one and add it to both Outlook and Thunderbird. Move your Outlook emails to Gmail's IMAP folder, which will sync with Thunderbird. Finally, move the emails from Gmail to Thunderbird's local folders. However, this process can be time-consuming, error-prone, and may fail if your mailbox is large.
Alternatively, the Migrate Cloud Data PST Converter Tool simplifies the process. It directly converts Outlook's PST files to Thunderbird's MBOX format, saving you from multiple configurations and potential sync issues. This tool is efficient, quick, and handles large file conversions without data loss, ensuring a smooth migration experience.