If you are a member of a list located on the vm6 list server and you have your Out of Office auto replies turned on, you will receive an error message from email@example.com with errors stating unknown commands. This is so everyone who is a also a member does not receive a copy of your Out of Office message.
It will look something like the following:
The mail server has encountered errors processing your request:
* Unrecognized command "test".
Please correct and resubmit your request(s). If you need further assistance, either use the Mail Server HELP command, or else contact the postmaster or administrator of this system.