Is it true that a Blocked Sender Policy is always checked before a Permit Sender Policy during email processing in Mimecast?

The statement that a Blocked Sender Policy is always checked before a Permit Sender Policy during email processing in Mimecast is accurate. In the Mimecast email flow, the evaluation of sender policies follows a specific sequence designed to enhance security and ensure that potentially harmful messages are filtered out effectively.

When an email is received, Mimecast first examines the Blocked Sender Policies to identify if the sender is on a blocklist. If an email originates from a blocked sender, it is immediately rejected or quarantined, preventing any chance of further processing. This approach prioritizes security by addressing threats upfront.

After addressing any blocked senders, Mimecast then checks the Permit Sender Policies. If a sender is on a permit list, their emails may bypass certain filters or be treated differently from others. However, if a sender is both blocked and permitted, the Blocked Sender Policy takes precedence to protect the organization from unwanted communications.

This hierarchical approach ensures that the most critical security measures are enforced first, thereby reducing the risk of malicious content reaching the inboxes of users.