Email lists are a great way to send emails to multiple recipients without have to manually enter every email address.  They can be set up as either open or closed lists, which determines whether or not people can subscribe to a particular list, or if they must be added by a list administrator.

If you need a mailing list and use Stony Brook's Google Apps service, please consider Google Groups.  If you're not sure which to use, please click here for a comparison.