MailStore - MailStore Home - A 100% free single-private-user desktop solution
Veeam Backup - Backup and restore VMware and Hyper-V virtual machines with Veeam Backup Free Edition. Unlimited hosts and VMs. Free forever.
Gmvault - Backup the emails in your Gmail account.
Zerto - Virtual replication & recovery solution
MailSteward - MailSteward : The Ultimate E-mail Manager for Mac OS X
Acronis Backup and Recovery - Acronis Backup is a data recovery solution that offers more ways of storing and recovering drives, folders and files as compared to other similar solutions.