Why do so many legitimate emails from companies still end up in my spam folder instead of the inbox when it’s really easy to prevent this from happening? Yes, the first email to a new recipient may, quite understandably, land in the junk mail—but not the second one! How much revenue is lost by customers not spotting these emails? According to various studies, companies actually lose millions of dollars every year due to this very issue.

Many customers forget to check their junk mail folder regularly—especially on smartphones, which have less screen space. Instead of trying to understand this behavior, I’d like to briefly look into why these missives land in junk mail at all.

Many email tools use a logic based on your list of contacts and sometimes on a safe list for certain newsletters and such. Once a genuine email has been moved from the junk folder to the inbox, any future email from the same address should land directly in the inbox. However, some companies use software that generates a unique email address for each email instead of using a saved one. The result is that every email lands in the spam folder. Without indulging in any name-dropping, I can tell you that even some very big companies actually get this wrong.