I can't find information regarding what the difference is between the 2 Related Lists that are added to the Contact/Lead Page Layout (Email Sends and Individual Email Results).
Actually there is documentation available. When you set up Marketing Cloud Connector, you would typically perform additional setup adding "Individual Email Results" and "Email Sends" to Contact and Lead page layouts as outlined in MCC configure Page Layouts
Note: I would not recommend "Email Sends" related list on Contact/Lead record level and would prefer it as a standalone tab.
Individual Email Results: As the name implies, is a tracking mechanism in place to see what Email communications have been sent to at Contact/Lead at the record level. And this related list is only populated
- When E-mail send takes place from Sales Cloud "Email Sends" and Individual tracking not disabled.
- Tracking individual emails via Marketing Cloud sends (Journey Builder or Content Builder), making sure you select the option "Send Tracking Data to Sales Cloud" checkbox.
- And only if we send an email using a Salesforce DE (standard or filtered) or a Shared Salesforce DE (standard or filtered). If we use Synchronized Data Extension or Custom DE, email tracking will not go back to Salesforce.
Email Sends: Has master-detail relationship with "Individual Email Results", if you closely observe in the data model. Used to
- Initiate Email Send using "Email Sends" Tab or "New Email Send" button at the record level to either a Report/Campaign
- By Default emails sent like this will be tracked at Contact/Lead record level unless you specify "Disable Individual Tracking" available in the form.
- Can show recent Email Send Reports with whole other metrics including individual email tracking results.
Additional documentation: Email Send Record