This feature can be used in a variety of ways. You can create private alias lists that allow you to send messages to a single address and have them go to multiple individuals. A special implementation of tm at Penn allows for class lists to be generated automatically for faculty. Every night the list is refreshed. You cannot presume that an intended recipient will read your message quickly, or even at all.
Most users have rather small disk space allocations on e-mail servers.
A single message from you can consume someone's entire allocation. And a small attachment sent to a large number of users can have just as devastating an effect on the network and the servers. Some departments offer advice on using e-mail for courses . In addition, there is a growing set of rules for users of Penn's electronic resources that may affect how one uses e-mail lists of all types, but especially large lists. Public bulletin boards, or conferencing, is available on the Internet through a facility called NetNews .