Email Open Rate

Open rate used to be the headline email metric. Today it is a noisy signal — useful in context, misleading on its own. This video explains what opens actually measure in modern clients, when Apple Mail Privacy Protection inflates numbers, and how to pair opens with clicks, conversions, and deliverability data.

Mailbox providers also use engagement as a reputation input. Opens can hint at inbox placement shifts when compared across domains — but only when you know which clients distort the data.

What an open actually measures

Most ESPs count an open when a tracking pixel loads. That requires images enabled and a client that fetches remote content. It is a proxy for attention — not a guaranteed read.

Apple Mail Privacy Protection pre-fetches pixels for many users, which can inflate open rates for Apple domains without reflecting true engagement. Comparing Apple opens to Gmail clicks often compares unlike things.

When open rate is still useful

• Trending opens on the same segment over time (same client mix).
• Relative gaps between mailbox providers on the same campaign.
• A/B subject line tests when click and conversion lift confirm the winner.
• Diagnosing sudden deliverability drops alongside seed tests and Postmaster data.

Better metrics to pair with opens

Click rate, conversion rate, revenue per recipient, and spam complaint rate tell you more about business outcomes and list health. For deliverability specifically, pair placement tests and domain-level engagement with — not instead of — open trends.

Reporting hygiene for teams

Dashboards that rank campaigns by open rate alone reward subject-line bait. Define success metrics per send type: flows might optimize conversion; newsletters might balance clicks and unsubscribes; re-engagement campaigns might prioritize confirmed clicks over phantom opens.

Learn more: Delivery volume as a target metric, and Retention marketing strategy.