The VPOP3 status monitor allows users to see what VPOP3 is doing, and also, optionally, to send/receive simple 'instant messages' between local users.
Different users can have different permissions for the status monitor. They can be set for all administrators or non-administrators on Services → Status Server → Permissions, or set for individual users in the Permissions tab when editing a user.
You can send short text messages between users using the 'instant messaging' facility in the status monitor. These can only contain text, and only between users on the same VPOP3 server. It does not allow access to other IM services.
VPOP3 writes a log file called 'VPOP3_IM.LOG' (and VPOP3_IM.LBK) containing all the instant messages sent between users. This can be useful for trouble-shooting or for monitoring messages between users (check any local privacy laws before using the log to monitor users)