Can we compare deliverability between email marketing platforms?

Updated sender guidelines have made inbox placement tougher than ever. When deliverability declines, many businesses instinctively blame their email platform. But is switching platforms really the solution? Can deliverability be compared across different ESPs (Email Service Providers)?

Let’s unpack this.

The Myth of the “Deliverability Test”

It’s common to see blogs comparing ESPs – ranking them based on features, functions, and supposed “deliverability scores.” These comparisons often rely on one-off tests sent to seed lists, which are small sets of test addresses managed by mailbox monitoring services.

That might sound scientific, but it’s not representative. Real deliverability is built over time, across thousands of real inboxes, with genuine engagement data and user feedback.

For an accurate comparison, you’d need to split your actual audience and run long-term campaigns on multiple platforms simultaneously. That’s not practical – and even then, user behavior and engagement would differ enough to skew results.

So, can you compare ESP deliverability? In practice, not really. But this doesn’t mean all ESPs are the same.