• by Ray Schultz , Columnist, February 20, 2019

Spam-box placement fell in 2018, partly because subscribers are more actively managing their inboxes, according to The 2019 Hidden Metrics Of Email Deliverability, a study released on Wednesday by Return Path.

The spam placement rate fell to 9% in 2018 compared to 14% in 2017 — a 5% decrease.

The rate fell for all industries.

The lowest spam-box rate was enjoyed by the distribution & manufacturing business — at 4%. At the other extreme, the education/nonprofit/government sector came in at 19%, with the worst performance overall. 

At the same time, the read rate, a metric largely determined by subject lines and timing, rose from 22% to 24%.

The distribution and manufacturing sector scored the highest read rate for the third year in a row, at 60%.

Theinsurance business was next, with 43%. Down at the bottom were the education/nonprofit/government field, with 16%, and the business and marketing industries, with 17%.

Meanwhile, the spam complaint rate jumped from 0.17% to 0.39%. And in a possible danger sign, the “deleted without reading” rate jumped from 12% to 16% — and it rose for all industries, with pet suppliers seeing a 6% increase, and other fields between 3% and 5%.

“A high deleted before reading rate is a sign of a failed campaign,” the study notes. “But a consistently high deleted without reading rate can be an indication of permission issues or a lack of satisfaction with your overall email marketing program.”

In another possible concern, the reply rate decreased by almost half from .11% in 2017. The average in 2018 was 0.06%. The telecommunications business declined by a full percentage point.

High reply rates are preferable, although they could also signal that people are trying to unsubscribe. The study does not encourage marketers to “try anything gimmicky to increase their reply rate. instead switch from your “noreply@” from: address to one that’s managed.”

“For several years now, major mailbox providers like Microsoft, Google, and Yahoo have been placing an increased focus on subscriber engagement as part of the spam filtering process,” states Tom Sather, senior director of research at Return Path. “This study demonstrates that keeping subscribers actively engaged with your email program is a major factor in email deliverability.”

Sather adds, however, that “fewer than one-third of marketers are tracking critical engagement metrics like read rate, forward rate, and complaints.”

Return Path studied global consumer data from more than 17,000 commercial senders, 2 million consumer panelists and 6.9 billion commercial email messages sent to Microsoft, Gmail, Yahoo, and AOL users between January 1, 2018, and December 31, 2018.