Spamville – our not-so-affectionate term for ending up in subscribers' spam folders – is every email marketer's worst nightmare. If we were professional athletes, Spamville would be a career-ending knee injury. Engagement rates, ROI, and – indirectly – sales, all depend on your readers actually seeing your content. When your message gets routed to spam folders, your content, however fantastic, becomes invisible. Think of the age-old question about the tree dropping in the forest with no one around to hear it.