Inbox placement rates fell in 2015 from 2014. Why? Maybe because marketers haven’t kept up with inbox placement’s recent evolution.
The rules of deliverability have changed over the last few years. Large mailbox providers are using new metrics to determine inbox placement rates and making more deliverability decisions at an individual mailbox level. It may be that marketers are not looking at the right metrics to understand the size and impact of delivery problems, and are using old metrics and rules of thumb to solve delivery issues when they do occur.
Key findings from the report are:
Deliverability is worse in 2015: Worldwide, just 79% of commercial email lands in the inbox. This means for every five emails sent, one never reaches the intended recipient. Instead, it’s either sent to a spam folder or goes missing — most likely, blocked by the mailbox provider. The global inbox placement rate has decreased by 4% since 2014, when we reported that 83% of email worldwide was reaching the inbox.
Deliverability is particularly worse in the U.S.: There was a sharp decrease in inbox placement in North America. U.S. senders saw nearly one in four emails land in the spam folder or go missing, with inbox placement dropping from 87% in 2014 to just 76% in 2015.
And particularly worse at Yahoo Mail: Marketers had a harder time reaching subscribers at Yahoo Mail in 2015. Inbox placement rates at the world’s second-largest email provider dropped 13% year-over-year. At Gmail, marketers reached the inbox at the same rate in 2015 as 2014, thanks in part to Gmail’s classification system for promotional emails. Inbox placement at Outlook.com improved slightly, with a 3% year-over-year increase.
So why are marketers not making it into the inbox? According to extensive machine learning models, two of the top three factors that drive inbox placement problems at the top mailbox providers are “new” metrics that most marketers don’t consider drivers of inbox placement rates:
-- Low read rate for the sender at the mailbox receiver (26% of campaigns with problems): Among active mailboxes, the read rate for the sending domain is low. Sending to mailboxes that don’t interact with your mail drives delivery issues for all mailboxes and some big mailbox providers.
-- Complaint rates (21% of campaigns with problems): A high percentage of mailboxes mailed to hit the “report spam” button for mail from a specific sender. High complaint rates drive a lot of problems. This “golden oldie” metric has been in use for years. The inverse of complaint rates, having users “rescue” messages from the spam folder, is also very important — it’s just very rare and didn’t make our top factors list.
-- Mailing to a lot of dormant mailboxes (19% of campaigns with problems): Mailing to many mailboxes that look like they’ve been abandoned drives down inbox placement for both dormant and live accounts.
This analysis and the changes to how deliverability works at top mailbox providers has created a few new deliverability rules for marketers:
Monitor deliverability “in the wild." Since some large ISPs filter at the individual mailbox level based on engagement, you need to understand what your inbox placement looks like in real live mailboxes at those ISPs that filter at the mailbox as well as the global level. Seed-address monitoring and SMTP reporting from your ESP are not enough by themselves.
Understand how your read rate compares. It appears that ISPs make global filtering decisions based on what percent of mailboxes read your mail. You need to understand where you stand relative to the read-rate thresholds for these larger ESPs.
Understand the kinds of mailboxes you are mailing to. Are you mailing to a bunch of dead mailboxes? If so, this might be the cause of your delivery issues at live accounts.
Look at complaints from active accounts and user surveys. It's still important to understand complaint rates. This factor hasn’t changed. However, analysis of complaint rate data would indicate that larger mailbox providers look at a variety of different transformations of complaint data to determine if mail is wanted. In particular, they look at complaints from live mailboxes and survey methods to determine complaints (such as Microsoft’s Sender Reputation Data panel).
The old reputation metrics still matter, but they’re just not at the top of the list. Hitting spam traps and mailing to nonexistent accounts at the mailbox providers still drive delivery issues. You should continue to monitor these factors, but they aren’t always the first place to start looking.
Let’s hope that marketers use new metrics and deliverability rules to show a global improvement in inbox placement rates.