In this day and age, most of us receive several e-mails a day. Depending on your job, you may even receive dozens of daily messages that are not spam. While it is hard enough to keep up with this plethora of e-mails received in a single day, if you fall behind a few days, it can be nearly impossible to catch up. After awhile, you may end up with hundreds of messages in your inbox that have not been replied to.