MailStore - MailStore Home - A 100% free single-private-user desktop solution
Gmvault - Backup the emails in your Gmail account.
SysTools Gmail Backup - Backup Gmail Emails, Contacts, Calendar, and Google Drive Storage File by SysTools Gmail Backup Solution
Mail Backup X - Your one stop mail backup and archiving tool for Mac.
Datto Backupify - Protect your business with backup.
PST to Office 365 Wizard - Outlook PST to Office 365 files converter tool supports multiple formats conversion.