I had been looking for the same thing earlier this year and had the same problem. Here's how we were thinking about it in the abscence of better benchmarking.
We gathered email metrics for:
Ourcustomer emails overall
The different types of customer newsletters (i.e. product newsletter vs content vs vertical-specific)
From there we were able to identify the weak spots for the customer newsletters - they were still driving opens, but clicks had decayed in 2026 (more so for content-focused newsletters).
Was definitely seeing that more sections are no longer better lol. Instead, people were more looking for tips, use cases, things that gave them more value and utility.
