Reputation: What it is and Why it Matters
A major principle in achieving stellar deliverability is, building, maintaining, and sometimes repairing sender reputation.
A sender’s reputation is exactly as it sounds. It’s how one is perceived by the receiving community (i.e. mailbox providers such as Gmail, Yahoo, filtering solutions, such as Proofpoint, Mimecast, Symantec, and hosting companies, such as NocRoom, GoDaddy and the like, as well as other receiving entities). It is important to note, both mailing IPs and domains are factored into the overall reputation equation.
As mentioned above, recipient engagement, or positive recipient interaction, is a key player in the overall reputation picture. In short, a client's deliverability success is highly dependent on that positive interaction. There are many different components of reputation but very heavily weighted is that recipient behavior / engagement metric.