You can try to use Advik Email Backup Wizard to download emails from Zimbra Mail to your computer in any format or email service you prefer. The software offers 30+ saving options with advanced features. Additionally, it is designed with advanced algorithms, making it user-friendly for everyone. The tool also comes with a free demo version that allows you to save a few emails from Zimbra desktop to your local storage. This lets you evaluate the tool before purchasing it. For unlimited backup Zimbra emails to your PC, you can buy the license keys.