Partial Backup Accomplished

My Passport Essential drive on my Windows 7 HP is not backing up all my email. It says that there are 81 email files on my computer (at 39.9MB) and that only 42 files (33.3MB) are backed up? The backup page on the program always says, “Partial Backup Accomplished”. That’s not helpful. How can I get it to backup completely?

Hello,

What email client you are using?