The best, most secure, and most reliable tool for macOS that helps backup and migrate Zoho mails is MacSonik Zoho Backup Tool for Mac. By using this tool you can download Zoho mails in PST, OST, EML, EMLX, MSG, and many more formats on macOS. The software has the capability to back up and migrate Zoho mail to Office 365, Gmail, iCloud, HostGator Emails, etc. It also maintains the folder hierarchy.