Inbox Placement Monitoring: Past, Present, Future

A question popped up recently on a private email list I participate in about the validity of seed lists to determine inbox placement rates. To answer that question, it helps to take a look at the evolution of the practice of deliverability and also give a peek into what the future might hold.

In the earliest days of email, monitoring your deliverability was relatively simple. Most ISPs had no spam folder, so if a message got rejected, you’d know it from the high amount of bounces in your bounce logs, or because your IT person was calling to say that the server was down because of the flood of rejected addresses returning back to your mail server through bounce messages. And if you weren’t monitoring your bounce logs or bounce mailbox, you’d surely notice when your response rates were below average. Then as spam increased, ISPs reacted by creating the spam folder and feedback mechanisms for subscribers like the “this is spam” button. If you garnered enough spam votes or your message looked like spam based on content, the ISP would deliver the message to the spam folder.

Marketers now had a new problem...