This is actually quite basic, but it is a goal that has remained in the background. What is it? It is attracting the interest of recipients in your list to provide they open the next email. It didn't seem familiar at first, did it? Even may, you said "are we really doing email marketing for this"? But what about the potential customer portfolio to become a real customer, sales goals? What happened to them? Ultimately, wasn't marketing, the ways and strategies to reach them?