If you are looking for the most secure utility to back up and migrate multiple different file formats and email programs. I will recommend to you Migrate Cloud Data's Email Migration Software that offers to back up and migrate data into various file formats and email clients (Office 365, Gmail, Yahoo, Thunderbird, AOL, Hotmail, etc.). Allows you to Input Multiple File Formats ( MBOX, PST, MSG, EML, etc.) and Export Data Into Various Email File Formats (PST, MBOX, EML, MSG, EMLX, etc.). Save Attachments Separately to PDF Format and many other features.