Its primary focus is to focus on the reply system instead of send system. As monitor and reply is the main hassle with owning so many email ids. And that's exactly what it is trying to solve. There are two kinds of products on market, one that tries to do all, competing against Gmail directly. Other types of products are niche-specific.
That's Mutant Mail, they are a solution to a specific problem of managing all domain's emails, from one Inbox, on the server-side, without the hassle of logging into each email id. And our settings, features, and roadmap reflect the same.