Making the Grade: It Takes an A-Level Reputation to Get to the Inbox
Unknown users are probably mistakes. They're accounts that have been decommissioned or never existed. They may be old addresses, but more likely they were keyed in wrong, either by users themselves or often by reps on the phone or at retail stores. The good news is that they're easy to find and remove. If mail is sent to these addresses, the sender will receive a bounce code clearly identifying them as unknown or invalid. Remove these right away or you signal to mailbox providers you don't pay attention to list hygiene.
Spam traps are unused email addresses that are monitored to detect senders who cannot possibly have permission to send mail to them. There are two types of spam traps: recycled and pristine. Recycled traps are formally valid addresses that have been repurposed to identify mailers who do not monitor their lists carefully. They've generally been sending "unknown user" bounce messages for a long time, so senders are expected to have removed them long before the monitoring begins. The other type is a pristine trap: an address that was never valid. Pristine traps are created to catch mailers who are sending to scraped addresses, guessed addresses, typo addresses (i.e., aoll.com), or to subscribers who could not possibly have opted in.
The Honor Society
Marketers who avoid these reputation missteps, who constantly monitor their complaint rates and list quality, and who otherwise follow best practices have high Sender Scores as a result. On the Sender Score scale, the top senders have a great reputation in the 91-100 range, and their messages make up two-thirds of all email delivered to the inbox. But there's remarkable variation within this range, and some senders in this honor society of email marketers far outperform their peers.
• Taking a Few Honors Classes (A- 91-94) Marketers in the 91-94 range are among the top performers, which means most of their messages are delivered to the inbox. But unlike their peers within the top scoring groups, they are not applying themselves to their full potential. Marketers in this band still maintain a few bad habits, which keep them from being at the top. These marketers have an average inbox placement of 87%, typically as a result of higher complaints and poor list quality.