Systems and methods for monitoring and/or auditing of events in an electronic messaging environment, such as Microsoft® Exchange, are described. One or more monitoring components are installed on messaging system servers to collect, in real-time, information on messaging system events. Certain embodiments are configured to audit and/or provide alerts regarding non-owner activity, such as when a user or administrator has gained access to another user's mailbox. Alerts can advantageously facilitate prompt corrective action by delivering detailed information about the access activity, such as which email message or folder was accessed, when the access occurred, from what location (e.g., IP address) when the access was initiated, and the type of access, as well as permission changes made to the mailbox or folders. The monitoring systems can also be configured to audit changes to client permissions for folders and delegate assignment and/or changes to configuration objects of the messaging system.