Utilize the GainTools MSG to MBOX Converter Tool to enjoy a smooth and trouble-free conversion of your email messages in less time. For managing big data sets, this feature-rich software is perfect as it offers batch conversion, free of file size limits. It fits with several email applications, including Eudora, Apple Mail, Thunderbird, and Postbox. It comes with a free trial version and tech help that's available 24/7.

For more: https://www.gaintools.com/msg/mbox/