How does Boomerang decide what emails to list as an unanswered item?

To ensure you're getting actionable emails, Boomerang uses advanced algorithms to identify messages with action items from people that are of some significance to you.

For example, an email from a random sender asking "Can we meet on Monday at 3 PM?" will be ignored by Brief Me. 

However, an email from your coworker Joe that says, "Can you send me this document?" will be recognized as an unanswered item if you haven't replied to that email yet.