ISPs determine inbox placement based on the reputation of the sender. Reputation can depend on a variety of factors, such as complaint rates (spam button), unknown user rates and spam trap hits.
Your opt-out process could be affecting your reputation. This might sound counter-intuitive, but ease of opt-out can be critical in protecting your email reputation. It is important that the opt-out process is made as easy and transparent as possible.
Customers receive a growing number of....