"Automated Activity Capture" came out in Sprint 17 (https://releasenotes.docs.salesforce.com/en-us/spring17/release-notes/rn_sales_einstein_automatic_activity_capture.htm) which allows for emails and calendar items to be automatically logged in Salesforce.
The challenge is that they can't be used in:
- Standard "Last Activity Date" field
This is excludes users who have this feature turned on from running reports like "Which of my open deals have I not contacted in the last week" and also a key field "Last Activity Date", which I personally use a lot in list views and reports, does not use any of the activity brought in using this.
For this to be a true core feature of sales AUTOMATION this needs to be exposed in the API, Reports, Workflow, etc.