Which of the following queues is monitored by Mimecast?

Mimecast primarily monitors the Outbound Queue to ensure that emails sent from the organization are processed and delivered efficiently and securely. This queue is crucial because it directly affects the communication flow between the organization and its stakeholders. Monitoring the Outbound Queue helps in identifying any issues that may prevent emails from reaching their intended recipients, such as server problems or configuration errors.

By keeping a close watch on this queue, Mimecast can provide insights and alerts regarding email deliveries, failures, or delays, allowing organizations to troubleshoot issues swiftly and maintain effective communication. This monitoring is essential for ensuring that email gateways operate optimally, minimizing downtime and disruption in email services.

In contrast, other queues such as Active Directory, Reports Queue, and Spam Queue serve different purposes. While they are important for their respective functionalities, they do not play as direct a role in the immediate processing and delivery of outbound emails as the Outbound Queue does.