How to Define and Remove Inactive Subscribers From Your Email List
Email marketers are quietly waging war against the unengaged and inactive subscribers who clog their lists and never engage with their marketing emails. Knowing that ISPs and mail servers allocate a sender score that determines where their email is delivered, the general goal is to eliminate addresses, improve your score and increase your inbox placement rate.
The unfortunate byproduct of this war on unengaged and inactive subscribers is the removal of subscribers who may appear to be unengaged or inactive, but are really very much alive. Take, for example, subscribers who read their email on their mobile device or use Gmail with images disabled by default. They never register an open, but still enjoy the steady rhythm of your email and are active customers on your website. Removing them comes at a significant price — the loss of a potential customer.
The simplest definition of an inactive subscriber is someone who no longer reads your email, but hasn't yet taken action to stop receiving it. Knowing exactly who is reading your email is impossible. Open and click measurements are clearly not perfect. They're sometimes over-represented and sometimes under-represented, depending on the situation. Plus, there's currently no way to measure views (i.e., emails that haven't been opened but are still acknowledged by the subscriber) in the subscriber's inbox. So you don't really know who is interacting with your email and who isn't.
Compared to other channels, sending email is relatively inexpensive, so there's little incentive to remove inactive subscribers beyond solving deliverability challenges. And while removing inactive addresses may help deliverability in the short term, increasing engagement through better email marketing is the only effective long-term solution.
Marketers need to avoid unnecessarily removing active subscribers. If you aren't experiencing deliverability challenges, then you should never throw away a perfectly deliverable email address.