When you send out a mass email your recipients interactions (opens, clicks, bounces and unsubscribes) will be stored in Campaign Monitor. Every hour (by default) Campaign Monitor for Salesforce used this information to update your Salesforce Contact and Lead records.
Campaign Monitor interactions then flow into Salesforce either creating or updating records. These records can be found in two places;
1. Subscriber list membership.
2. Email tracking statistics.
We display this information on a related contact or lead as per the screenshot below.
If a person unsubscribes from a Campaign Monitor subscriber list their state will be updated changing from active to unsubscribed. If a person has unsubscribed from all lists then we can optionally update the standard email opt-out field, you can learn more here
. Similarly, if a person record has hard bounced then their subscriber member state will be updated. To find out more in Campaign Monitor bounce types click here