• by George Bilbrey , Op-Ed Contributor, August 6, 2014

For all the talk about how email deliverability is evolving, I don’t hear enough specificity about what, exactly, has changed. If you’ve noticed this too, here’s a quick explanation of what’s different about inbox placement and how you can stay ahead of the shift by asking the right questions.

The big change in deliverability is mailbox providers’ recent expansion from global filtering into subscriber-level filtering. Global filtering is based on sending domains or servers, counting complaints and messages sent to spam traps. Global filtering is still used to identify really bad spammers, and it’s still an important component of inbox placement decision making, but more mailbox providers are adding subscriber-level filtering to determine what gets delivered to users’ inboxes. By applying a new set of metrics based on individuals’ interactions with specific senders, major mailbox providers are making more sophisticated inbox placement decisions, but they’re also making it harder to diagnose deliverability problems and to set policies that ensure your messages get to your subscribers.

Whether you manage your deliverability in-house, through a specialized provider, a consultant, or your ESP, the answers to these three fundamental questions hold the keys to staying connected to your subscribers:

1. Did my mail get there? Answering this question in 2014 means getting SMTP data by domain, and not based on mail transmission, because the receiving mail server generally counts as “delivered” messages routed to junk or dropped at the gateway.

Mailbox providers are evolving their inbox placement decision-making at different rates; some aren’t using subscriber-level filtering yet. That means that you need a seed list to monitor deliverability across the spectrum of providers, ideally including as many as possible for a “long tail” view of the landscape. Meanwhile, you need a sample of subscribers “in the wild” to show you whether you’re reaching the inbox at Gmail, Outlook.com, Yahoo and other mailbox providers that factor individual users’ interaction patterns into their decisions. To reliably detect deliverability trends for your campaigns, this sample needs to be big.

2. Why wasn’t my mail delivered? This is where subscriber-level filtering complicates deliverability troubleshooting. Monitoring blacklists is still important, and so are the number of complaints and messages sent to spam traps and unknown users.

But three engagement metrics can help you diagnose problems by seeing your mail the way mailbox providers do:

• Read rate, which is different from open rate because it’s calculated from IMAP flags, the same way mailbox providers do it.
• Read frequency, or the percentage of users who frequently read your messages.
• Inactive ratio, or the percentage of mailboxes on your list that are totally inactive, or dead.

3. What can I do, right now, to fix the problem? This is not unanswerable, but it weeds out the folk remedies and blanket solutions of a simpler deliverability era from the more analytical approach required today. If you or your deliverability experts have access to subscriber engagement metrics and experience diagnosing situations similar to yours — in your industry — you can quickly identify prescriptive actions that immediately improve inbox placement at specific mailbox providers. For example removing (or better, reengaging) inactive subscribers can alleviate deliverability problems.

It’s true that the deliverability world has changed, and it will only become more complicated in the future, but making sure that your deliverability team can get you accurate, reliable, data-driven answers to these questions will keep you connected to your subscribers and protect your email marketing performance and revenue.