Emails reveal Clinton asked to borrow a book containing tips on deleting messages

The latest string of private Hillary Clinton emails made public by the Justice Department includes one message that may raise some red flags. The 2016 presidential candidate reportedly asked to borrow a book that explains how to permanently erase emails.

Clinton requested the book "Send: Why People Email So Badly and How to Do It Better." ABC News purchased a copy and was surprised when they read the table of contents. The book contains a chapter titled "The Email That Can Land You In Jail" and includes a section called "How to Delete Something So It Stays Deleted."

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"Some people are hoarders, some are checkers," the authors write. "The main thing to consider is that once you do decide to delete, it's like taking the garbage from your kitchen and putting it in your hallway. It's still there."

The book explains that to truly delete an email, the user must use a special rewriting program -- but notes that if you're ever given a subpoena, the program will make you look guilty.

The Justice Department is currently investigating whether or not Clinton used her private email server to send classified information.

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