On the back end, Lightning Experiences is relied upon with Salesforce for Outlook for both users working in Lightning Experience and Salesforce Classic. There are limitations for Salesforce Classic to interpret APEX Calls. Salesforce for Outlook has relied on Lightning Experience to interpret APEX calls made from Internet Explorer 11. Email Tracking for Emails in Lightning for Outlook Email Clients & Office Suites Currently, when you send an email to a Contact through the Lightning interface a tracking pixel is automatically added to the outgoing email (provided you have this feature enabled for your organisation).
