If you want a quick and reliable way to convert or import MBOX to Yahoo Mail without losing any data, try Advik MBOX Converter Software. This easy-to-use tool has powerful features and works well with all Windows versions. It can transfer large MBOX files with attachments to Yahoo Mail account in bulk, all within just a few steps—often in under 60 seconds.

The tool supports MBOX files from email clients like Apple Mail, Eudora, SeaMonkey, Thunderbird, and more. You can also test the free trial version, which lets you convert up to 25 emails.