How can organizations verify the effectiveness of their Mimecast deployment?

Utilizing reports and regular assessments is a crucial method for verifying the effectiveness of a Mimecast deployment. Through these reports, organizations can evaluate key performance indicators such as the success rates of email filtering, the number of threats detected and mitigated, the performance of the designated policies, and overall user engagement with the Mimecast system. Regular assessments provide a structured approach to review and adjust security measures based on real-time data and trends. This proactive monitoring helps identify potential vulnerabilities and areas for improvement, ensuring the deployment remains effective against evolving threats.

The other options provided do not effectively address the verification of deployment effectiveness. Surprise audits might provide insights but lack the ongoing, systematic review that regular assessments offer. Increasing user accounts does not directly relate to assessing deployment efficacy; it merely demonstrates growth in usage. Resetting all user passwords is a reactive measure to enhance security but does not pertain to evaluating or confirming the overall system's effectiveness.