MacSonik Office 365 Email Backup Tool for Mac is the best Email Backup Tool . It has the capability to export Office 365 Mailbox to PST, MBOX, EML, EMLX, HTML, MHTML, and many other CSV file formats. It gives multiple features like restoring PST Data to Office 365 Account, Selective Backup of Office 365 Emails, Import CSV for Backup Office 365 Account, and Save Output by Chosen Folder Name. It also offers a Mail filter & task filter option to download Office 365 Mailbox to PST from a specific date range.