Deliverability is a function of engagement over time, so something has been going amiss for at least a couple of weeks by the time you notice a drop in inbox rates. It’s imperative to react quickly to minimize any additional reputation damage while you dig into the root of the problem. One of the tactics I recommend is to maintain a list of subscribers that are your most active subscribers. This is easy to do before you run into problems and should be refreshed monthly.
To create this list of core subscribers, you’ll want to run a report showing which subscribers have engaged with your email multiple times. Limit your search to the last three months. Focus on recent opens and clicks, and prioritize subscribers who regularly open and/or click your messages. These subscribers drive up your engagement metrics dramatically.
As soon as you start to see a drop in deliverability, open, or click rates, you’ll want to change your list to your core subscribers plus about 20% more less engaged subscribers for the next few sends. For example, if you have 10,000 core subscribers your total send volume will be 12,000 for the next two to three sends. Slowly add in subscribers who haven’t engaged recently, so your next send might be 14,000 subscribers and include subscribers who haven’t opened or clicked in four to five months.
There will come a point when you’ll see a dramatic drop in your open and click rates for your sends. Once that happens, remove the last batch you added and create a re-engagement campaign for any addresses of that age and older, or suppress all older addresses from all subsequent sends.
While this won’t get you to the root of the issue, it will allow you to continue marketing while you work on finding the root cause and creating a plan to address it. If you need some help with setting up processes for immediate remediation tactics or with getting to the root cause, you can contact me through the Contact form or email me at firstname.lastname@example.org.