Which group is likely to include senders that have been explicitly allowed through the Mimecast system?

The X-Permitted Senders Group is specifically designed to include senders that have been explicitly allowed through the Mimecast system. This group is essential for identifying and managing trusted sources of email that are permitted to bypass certain security checks or filtering mechanisms implemented by Mimecast. The purpose is to ensure that emails from these senders are not mistakenly marked as spam or subject to unnecessary filtering, thereby maintaining the integrity of communications from trusted sources.

The Whitelist Group also includes allowed senders but is generally a broader term that may lack the specific operational context tied to Mimecast's functionalities. On the other hand, the Blocked Senders Group is meant for senders that are prohibited from delivering emails through the Mimecast service, while Managed Senders refers to a defined group of senders that may have special management or monitoring configurations but does not necessarily imply they are explicitly permitted. This distinction highlights the unique nature of the X-Permitted Senders Group within the email security framework provided by Mimecast.