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Deliverability Letter

Open Rate (OR)

The percentage of delivered emails that people open. Useful as a quick health check on subject lines and inbox placement, but it does not show real engagement on its own.

Open rate is the share of delivered emails that people open. Your email tool tracks this with a tiny hidden image that loads when someone opens the email. If images do not load, the open may not be counted. This means the real open rate is usually a bit higher than what you see in reports.

Marketers use open rate as a quick health check for their email program. A drop in open rate can point to weak subject lines, spam issues, or a cold list. A steady or rising open rate can signal good list quality and subject line fit. It is helpful, but it does not tell you whether people read or clicked.

Use open rate alongside click rate or click to open rate. For example, if you send 1,000 emails, 900 are delivered, and 180 are opened, your open rate is 20 percent. Track these numbers over time for each segment. Then test one change at a time, such as subject line, sending time, or audience.