Explanation
The Email Send Report in Analytics Builder is the best place to view the total number of emails sent across all business units in the last calendar year. This report provides a summary of email performance metrics such as sends, opens, clicks, bounces, and unsubscribes for a specified time period.

Explanation
To address the issue of employees not receiving emails because the messages are being blocked by spam filters, the Marketing Cloud admin should provide the IT team a list of relevant IP addresses to whitelist in their spam filter. Whitelisting is a process that allows NTO to specify which IP addresses are trusted and can bypass the spam filter. By providing the IT team a list of relevant IP addresses, such as the ones used by Marketing Cloud to send emails, the admin can ensure that the emails from NTO will not be blocked or marked as spam by the employees' email servers. The other options are incorrect because:
* Import employee email addresses into All Subscribers with an "Active" status. This option will not address the issue, as it only affects the subscription status of the employees in Marketing Cloud, not in their email servers. Importing employee email addresses into All Subscribers with an "Active" status means that NTO can send emails to those employees from Marketing Cloud, but it does not guarantee that the emails will be delivered or received by the employees' email servers.
* Ensure employees have opted in to the test email list or data extension. This option will not address the issue, as it only affects the consent of the employees to receive emails from NTO, not their email servers. Ensuring employees have opted in to the test email list or data extension means that NTO has permission to send emails to those employees, but it does not guarantee that the emails will be delivered or received by the employees' email servers.
* Ask employees to use personal email addresses instead of corporate email addresses. This option will
* not address the issue, as it only shifts the problem from one email server to another, not solving it.
Asking employees to use personal email addresses instead of corporate email addresses means that NTO will send emails to different email servers, but it does not guarantee that those email servers will not block or mark the emails as spam.