Add emails to Salesforce records from the 'Salesforce for Outlook' Side Panel

Add Emails to Multiple Salesforce Records That Accept Tasks
 

With SFO version 3.0 and newer you can now add emails to multiple Salesforce records that accept tasks, such as Accounts, Person Accounts, Opportunities, Custom Objects and Cases—not just Contacts.

This means that you are no longer limited to adding emails to only one record that accepts tasks.
 

• Before Spring 15, Salesforce Administrators could allow Users to relate up to 50 Contacts to a Task or Event (except a recurring one) by enabling the "Allow Users to Relate Multiple Contacts to Tasks and Events" feature from Setup | App Setup | Customize | Activities | Activity Settings in Salesforce Classic or Feature settings | Sales | Activity Settings in the Lightning Experience UI.
• Since the Spring 15 Release, the above feature does not even have to be enabled if you decide to enable the permission below. Users are able to associate emails to multiple records.

Note: 

• Salesforce creates separate tasks for each record to which users add emails.
• With the permission enabled, when associating a task to a Contact and Opportunity, the Related To and Name lookup fields will no longer be populated with the corresponding Contact and Opportunity.
• If the permission is disabled on a later date, the previously associated records remain intact. The Users will no longer have the ability to associate tasks to multiple records as noted above.