Unsubscribe rate is the percentage of recipients who opted out of your emails after a given send.
In depth
A low, stable unsubscribe rate, commonly under 0.5 percent, is normal and even healthy because it removes disengaged people. A sudden spike signals a problem such as irrelevant content, sending too often or a poor list source. Always make unsubscribing easy, and consider a preference centre so people can reduce frequency instead of leaving entirely.
Example
If 10,000 emails are delivered and 30 people unsubscribe, the unsubscribe rate is 0.3 percent.
Related terms
See our full email marketing glossary or the complete email marketing guide.