| Open rate This is the ratio of unique opens to messages delivered. A high open rate means that your customers are engaging with your emails, which has a positive impact on deliverability rate. | How to increase your open rate |
| Click rate This is the ratio of unique clicks to messages delivered. A high click rate also means that your customers are engaging with your emails. However, mailing services don’t consider click rate percentage as important as the open rate percentage. | How to increase your click rate |
| Unsubscribe rate This is the ratio of people who unsubscribed to the total number of messages delivered. If your unsubscribe rate percentage is high, this shows mailing services that customers are receiving irrelevant content or that they didn’t give their permission to get your emails. As a result, your deliverability rate suffers. | How to reduce your unsubscribe rate |
| Bounce rate This is the ratio of undelivered messages (due to the addresses being invalid) to the total number of messages sent. This metric helps you assess the quality of your email list. A high hard bounce rate indirectly shows that either your email list is outdated, your subscribers didn’t opt-in to receive your emails, or they didn’t confirm their subscription. | How to reduce your bounce rate |
| Spam rateThis is the ratio of messages reported as spam to the total number of messages delivered. Mailing services view spam reports as a customer action that negatively impacts deliverability. | How to reduce your spam rate |