What Is an Open Rate for Newsletters? Formula and Why It Is Unreliable
A newsletter open rate is the percentage of delivered emails that were recorded as opened, calculated as opens divided by delivered emails. It is measured by a tiny tracking image that loads when the message is displayed.
The formula is opens ÷ delivered emails × 100, usually using unique opens so one person opening twice counts once. A newsletter sent to 1,000 people with 400 unique opens has a 40% open rate. The number depends on how your email platform counts opens and whether it excludes bot activity, so compare only within the same tool.
Open rate has become a noisy metric. Some mail apps, notably Apple Mail with its Mail Privacy Protection, pre-load tracking images for the reader, which can register an open when no human saw the message. That inflates the rate and makes comparisons over time unreliable. Image-blocking works the other way, hiding real opens.
So use open rate as a rough directional signal, for example to compare two subject lines sent to similar segments at the same time, and put more weight on clicks, replies and conversions. Sender reputation, list quality and subject line all influence it, and sending to people who no longer engage will pull it down and can hurt deliverability. A newsletter that is part of a wider sequence (see what-is-an-email-sequence) should be judged on what readers do next.
Why it matters
Infinall AI turns a product URL into competitor research, strategy, ad copy and creative that land in an Approval Queue for you to review before export. It does not send newsletters or measure open rates, and it cannot tell you how your list is performing. If you run a newsletter as a digital product, Infinall can help you draft promotional angles and creative for growing the list, which you review and approve before export. Reading your own open, click and unsubscribe data stays in your email platform.
Related terms
Frequently asked questions
What is a good newsletter open rate?
There is no trustworthy universal benchmark, because tracking differences and privacy features make rates inconsistent across tools and audiences. Compare your own rate over time and between segments within the same platform. Treat a sudden change as a prompt to check deliverability and subject lines, not as proof of a trend.
Why did my open rate jump after Apple's privacy change?
Mail Privacy Protection pre-fetches email content, including tracking images, for people who enable it. That can count as an open even if the person never read the email. Clicks, replies and conversions are less affected, so they are better indicators of genuine engagement.