Building on the recent launch of aggregate reports in Admin console, google launched additional time-series reports for Gmail, with the goal of providing admins more visibility into mail flow.
New reports include:
Outbound Mail Delivery
Outbound Mail Encryption
Inbound Mail Delivery
Inbound Mail Encryption
For more detail on these new reports, check the Gmail section of the aggregate reports Help Center article.
To access the aggregate reports dashboard, sign in to the Admin console and click Reports > Aggregate Reports