Well, it is kinda used for a lot more than basic inter office messaging. With Warp Server/WSeB, it can also report to any or all login groups or select users; things like machine status, shutdown alerts, etc. For instance, if you have a WSeB/Warp Server unit that is hooked up to a UPS, and power goes out, you can have the WSeB unit alert all/select users/groups that "The Server ##### is shutting down in ## minutes, please save all work and close all connections to the server." It can also (on most IBM Netfinity machines and the IBM Intellistations based off the Netfinity line) alert select users/groups about things like "Warning, the video card in Server ## is failing."/"Warning, hard disk failure expected." In addition, on WSeB/Warp Server units with HPFS386, it can warn about hard drive directory quota limit issues (such as a user directory getting near full, or a particular disk getting near full - all thresholds set by simple configuration).
Of course, with the power and flexibility of REXX on OS/2, it can also be used to alert anyone of your choice of about anything you want at any time you want - only limited by your REXX programming capabilites.
HTH,
Robert