What are the general rules of etiquette on any email list?
Messages sent to the email list address (which is private) go out to everyone on the email list. As such you may be tempted to treat them as public messages. They are not public messages! You should treat them as private messages sent out to all subscribers. That means you should respect the privacy and integrity of the person who sent the message. You should not quote from, forward, or reprint any message on a email list without first getting permission from the person who wrote the message.
